TWI889758B - Anti-corrosion agent composition and method for producing anti-corrosion agent pattern - Google Patents

Abstract

The present invention aims to provide a compound capable of producing an anti-etching pattern with good CD uniformity (CDU) and an anti-etching composition containing the compound. The anti-etching composition comprises a compound represented by formula (I), a resin having an acid-labile group, and an acid generator. [In formula (I), ^R1 represents a halogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms. m1 represents an integer from 1 to 5. When m1 is 2 or greater, multiple ^R1s may be the same or different.]

Description

Anti-corrosion agent composition and method for producing anti-corrosion agent pattern

The present invention relates to an anti-corrosion agent composition and a method for producing an anti-corrosion agent pattern using the anti-corrosion agent composition.

Patent Document 1 describes an anti-corrosion agent composition comprising a compound of the following structural formula, a resin having an acid-labile group, and an acid generator. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2000-066406

[The problem that the invention aims to solve]

The present invention provides an anti-etching composition comprising a compound capable of forming an anti-etching pattern having improved CD uniformity (critical dimension uniformity, CDU) compared to an anti-etching pattern formed by an anti-etching composition containing the compound. [Means for Solving the Problem]

The present invention includes the following inventions: [1] An anti-corrosion agent composition comprising a compound represented by formula (I), a resin having an acid-labile group, and an acid generator. [In formula (I), R ¹ represents a halogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms. m1 represents any integer from 1 to 5. When m1 is 2 or greater, multiple R ^1s may be the same or different.] [2] The anti-corrosion agent composition according to [1], wherein R ¹ is a fluorine atom, an iodine atom, or a trifluoromethyl group. [3] The anti-corrosion agent composition according to [1] or [2], wherein m1 is any integer from 1 to 3. [4] The anti-corrosion agent composition according to any one of [1] to [3], wherein R ¹ contains at least one iodine atom. [5] The anti-corrosion agent composition according to any one of [1] to [4], wherein the content of the compound (I) is 0.001% by mass to 20% by mass based on the solid content. [6] The anti-corrosion agent composition according to any one of [1] to [5], wherein the resin having an acid-labile group comprises at least one selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2). [In formula (a1-1) and formula (a1-2), ^La1 and ^La2 each independently represent -O- or *-O-( _CH2 ) _k1 -CO-O-, k1 represents any integer from 1 to 7, and * represents a bond with -CO-. ^Ra4 and ^Ra5 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ^Ra6 and ^Ra7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic alkyl group having 3 to 18 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, or a combination thereof. m1 represents any integer from 0 to 14. n1 represents any integer from 0 to 10. n1' represents any integer from 0 to 3. ] [7] The anti-corrosion agent composition according to any one of [1] to [6], wherein the resin having an acid-labile group further comprises a structural unit represented by formula (a2-A). [In formula (a2-A), R ^a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R ^a51 represents a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A ^a50 represents a single bond or *-X ^a51 -(A ^a52 -X ^a52 ) _nb -, where * represents the bonding site to the carbon atom to which -R ^a50 is bonded. A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms. X ^a51 and X ^a52 each independently represent -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents any integer from 0 to 4. When mb is any integer greater than 2, a plurality of R ^a51 may be the same as or different from each other. [8] The anti-corrosion agent composition according to any one of [1] to [7], wherein the acid generator comprises a salt represented by formula (B1). [In formula (B1), Q ^b1 and Q ^b2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L ^b1 represents a divalent saturated alkyl group having 1 to 24 carbon atoms, wherein -CH ₂ - in the divalent saturated alkyl group may be substituted with -O- or -CO-, and the hydrogen atom in the divalent saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic alkyl group having 3 to 24 carbon atoms, wherein -CH ₂ - in the alicyclic alkyl group may be substituted with -O-, -S(O) ₂ -, or -CO-. Z ⁺ represents an organic cation. ] [9] The anti-etching agent composition as described in any one of [1] to [8], further containing a salt generated by an acid with a weaker acidity than the acid generated by the acid generator. [10] A method for producing an anti-etching agent pattern, comprising: (1) applying the anti-etching agent composition as described in any one of [1] to [9] on a substrate; (2) drying the applied composition to form a composition layer; (3) exposing the composition layer; (4) heating the exposed composition layer; and (5) developing the heated composition layer. [Effects of the invention]

By using the anti-etching composition containing the compound of the present invention, an anti-etching pattern with good CD uniformity (CDU) can be produced.

In this specification, the term "(meth)acrylic monomer" refers to at least one monomer selected from the group consisting of monomers having a " _CH2 =CH-CO-" structure and monomers having a " _CH2 =C( _CH3 )-CO-" structure. Similarly, "(meth)acrylate" and "(meth)acrylic acid" refer to "at least one monomer selected from the group consisting of acrylates and methacrylates" and "at least one monomer selected from the group consisting of acrylic acid and methacrylic acid," respectively. When a structural unit having " _CH2 =C( _CH3 )-CO-" or " _CH2 =CH-CO-" is exemplified, a structural unit having both groups is also exemplified. "Derived from" or "derived from" means that the polymerizable C=C bond contained in the molecule is converted into a -CC- group through polymerization. Furthermore, the groups described in this specification may have either a linear or branched structure. A "combined group" refers to a group formed by bonding two or more of the exemplified groups. The valence of these groups may be appropriately modified depending on the bonding configuration. If stereoisomers exist, all stereoisomers are encompassed. In this specification, the "solid content of the anti-etching agent composition" refers to the total amount of the anti-etching agent composition excluding the solvent (E), described below.

<Anti-Corrosion Agent Composition> The anti-corrosion agent composition of the present invention contains a compound represented by formula (I) (hereinafter sometimes referred to as "Compound (I)"), a resin having an acid-labile group (hereinafter sometimes referred to as "Resin (A)"), and an acid generator (hereinafter sometimes referred to as "Acid Generator (B)"). The "acid-labile group" herein refers to a group having a cleavable group that undergoes cleavage upon contact with an acid, converting to a constituent unit having a hydrophilic group (e.g., a hydroxyl group or a carboxyl group). The anti-corrosion agent composition of the present invention may further contain a resin other than Resin (A). The anti-etching agent composition of the present invention preferably contains a quencher such as a salt generated from an acid weaker than the acid generated from the acid generator (hereinafter sometimes referred to as "quencher (C)") and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)").

<Compound (I)> The anti-corrosion agent composition of the present invention contains compound (I). [In formula (I), all symbols have the same meanings as described above.]

Examples of the halogen atom in ^R1 include fluorine, chlorine, iodine, and bromine. Examples of the fluorinated alkyl group having 1 to 6 carbon atoms in ^R1 include trifluoromethyl, difluoromethyl, perfluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, perfluoropropyl, 2,2,3,3,3-pentafluoropropyl, perfluorobutyl, 1,1,2,2,3,3,4,4-octafluorobutyl, perfluoropentyl, 2,2,3,3,4,4,5,5,5-nonafluoropentyl, and perfluorohexyl. m1 is preferably an integer from 1 to 3. ^R1 is preferably a fluorine atom, an iodine atom, or a perfluoroalkyl group having 1 to 3 carbon atoms, more preferably a fluorine atom, an iodine atom, or a trifluoromethyl group, and even more preferably a fluorine atom or an iodine atom. In addition, ^R1 preferably contains at least one iodine atom. When m1 is 1, ^R1 is preferably bonded to the vicinal or meta position relative to the carboxyl group of the benzene ring, and more preferably to the vicinal position.

Examples of the compound (I) include compounds represented by the following formulae.

The content of compound (I) is generally 0.001% by mass to 20% by mass, preferably 0.005% by mass to 15% by mass, and more preferably 0.01% by mass to 10% by mass, based on the solid content of the anti-corrosion agent composition.

<Resin (A)> Resin (A) contains a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). Resin (A) preferably further contains structural units other than structural unit (a1). Examples of structural units other than structural unit (a1) include structural units not having an acid-labile group (hereinafter sometimes referred to as "structural unit (s)"), structural units other than structural unit (a1) and structural unit (s) (for example, structural units having a halogen atom described below (hereinafter sometimes referred to as "structural unit (a4)"), structural units having a non-isolated hydrocarbon group described below (hereinafter sometimes referred to as "structural unit (a5)"), and other structural units derived from monomers known in the art.

<Structural unit (a1)> Structural unit (a1) is derived from a monomer having an acid-labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid-labile group contained in resin (A) is preferably a group represented by formula (1) (hereinafter also referred to as group (1)) and/or a group represented by formula (2) (hereinafter also referred to as group (2)). [In formula (1), ^Ra1 , ^Ra2 , and ^Ra3 each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic alkyl group having 3 to 20 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, or a combination thereof; or ^Ra1 and ^Ra2 are bonded to each other and, together with the carbon atoms to which they are bonded, form a non-aromatic alkyl ring having 3 to 20 carbon atoms. Ma and Na each independently represent 0 or 1, and at least one of Ma and Na represents 1. * represents a bonding site.] [In formula (2), Ra1 ^' and ^Ra2' each independently represent a hydrogen atom or a alkyl group having 1 to 12 carbon atoms, Ra3 ^' represents a alkyl group having 1 to 20 carbon atoms, or Ra2 ^' and Ra3 ^' are bonded to each other and, together with the carbon atoms to which they are bonded and X, form a heterocyclic ring having 3 to 20 carbon atoms, wherein the _-CH2- group contained in the alkyl group and the heterocyclic ring may be substituted with -O- or -S-. X represents an oxygen atom or a sulfur atom. Na' represents 0 or 1. * represents a bonding site.]

Examples of the alkyl group in R ^a1 , R ^a2 , and R ^a3 include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl. Examples of the alkenyl group in R ^a1 , R ^a2 , and R ^a3 include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, and nonenyl. The alicyclic alkyl group in R ^a1 , R ^a2 , and R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic alkyl group include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic alkyl groups include decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates a bonding site). The alicyclic alkyl group in ^{R a1} , R ^a2 , and R ^a3 preferably has 3 to 16 carbon atoms. Examples of the aromatic hydrocarbon group in R ^a1 , R ^a2 and R ^a3 include aryl groups such as phenyl, naphthyl, anthracenyl, biphenylyl and phenanthrenyl. Examples of the combined groups include groups formed by combining the above-mentioned alkyl groups with alicyclic alkyl groups (for example, alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl, dimethylcyclohexyl, methylnorbornyl, cyclohexylmethyl, adamantylmethyl, adamantyldimethyl, and norbornylethyl); aralkyl groups such as benzyl; aromatic alkyl groups having an alkyl group (such as p-methylphenyl, p-tert-butylphenyl, tolyl, xylyl, cumenyl, mesityl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl); aromatic alkyl groups having an alicyclic alkyl group (such as p-cyclohexylphenyl and p-adamantylphenyl); and aryl-cycloalkyl groups such as phenylcyclohexyl. Preferably, ma is 0 and na is 1. When ^Ra1 and ^Ra2 bond to each other to form a non-aromatic hydrocarbon ring, the following rings can be cited as -C( ^Ra1 )( ^Ra2 )( ^Ra3 ). The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * indicates the bonding site to -O-.

Examples of the alkyl group in R ^a1' , R ^a2' , and R ^a3' include alkyl groups, alicyclic alkyl groups, aromatic alkyl groups, and groups formed by combining these groups. Examples of the alkyl and alicyclic alkyl groups include the same groups as those listed for R ^a1 , R ^a2 , and R ^a3 . Examples of the aromatic alkyl group include aryl groups such as phenyl, naphthyl, anthracenyl, biphenylyl, and phenanthrenyl. Examples of the combined groups include groups formed by combining the above-mentioned alkyl groups with alicyclic alkyl groups (for example, alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl, dimethylcyclohexyl, methylnorbornyl, cyclohexylmethyl, adamantylmethyl, adamantyldimethyl, and norbornylethyl), aralkyl groups such as benzyl, aromatic alkyl groups having an alkyl group (such as p-methylphenyl, p-tert-butylphenyl, tolyl, xylyl, cumenyl, mesityl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl), aromatic alkyl groups having an alicyclic alkyl group (such as p-cyclohexylphenyl and p-adamantylphenyl), and aryl-cycloalkyl groups such as phenylcyclohexyl. When Ra2 ^' and Ra3 ^' are bonded to each other and form a heterocyclic ring together with the carbon atoms to which they are bonded and X, the following rings can be listed as -C( ^Ra1' )(Ra2 ^' )- ^XRa3' . * indicates a bonding site. At least one of Ra1 ^' and Ra2 ^' is preferably a hydrogen atom. na' is preferably 0.

As the group (1), the following groups can be cited. In formula (1), ^Ra1 , ^Ra2 , and ^Ra3 are alkyl groups, ma = 0, and na = 1. The group is preferably a tert-butyloxycarbonyl group. In formula (1), ^Ra1 , ^Ra2 , and the carbon atoms to which they are bonded together form an adamantyl group, ^Ra3 is an alkyl group, ma = 0, and na = 1. In formula (1), ^Ra1 and ^Ra2 are each independently an alkyl group, ^Ra3 is an adamantyl group, ma = 0, and na = 1. As the group (1), the following groups can be cited specifically. * indicates a bonding site.

As specific examples of the group (2), the following groups can be cited. * indicates a bonding site.

The monomer (a1) is preferably a monomer having an acid-labile group and an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer having an acid-labile group.

Among (meth)acrylic monomers having an acid-labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferred. When a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in an anti-etching composition, the resolution of the anti-etching pattern can be improved.

Examples of the structural unit derived from the (meth)acrylic monomer having group (1) include a structural unit represented by formula (a1-0) (hereinafter, sometimes referred to as "structural unit (a1-0)"), a structural unit represented by formula (a1-1) (hereinafter, sometimes referred to as "structural unit (a1-1)"), or a structural unit represented by formula (a1-2) (hereinafter, sometimes referred to as "structural unit (a1-2)"). Preferably, at least one structural unit selected from the group consisting of structural units (a1-1) and structural units (a1-2) is used. These may be used alone or in combination of two or more. [In formula (a1-0), formula (a1-1), and formula (a1-2), ^La01 , ^La1 , and ^La2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, k1 represents any integer from 1 to 7, and * represents the bonding site with -CO-. ^Ra01 , ^Ra4 , and ^Ra5 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ^Ra02 , ^Ra03 , and ^Ra04 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic alkyl group having 3 to 18 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, or a combination thereof. R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic alkyl group having 3 to 18 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, or a group formed by combining these groups. m1 represents any integer from 0 to 14. n1 represents any integer from 0 to 10. n1′ represents any integer from 0 to 3.

^Ra01 , ^Ra4 , and ^Ra5 are preferably a hydrogen atom or a methyl group. ^La01 , ^La1 , and ^La2 are preferably an oxygen atom or *-O-( _CH2 ) _k1 -CO-O- (wherein k1 is preferably any integer from 1 to 4, more preferably 1), and more preferably an oxygen atom. As the alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and group formed by combining these in ^Ra02 , ^Ra03 , ^Ra04 , ^Ra6 , and ^Ra7 , the same groups as those listed for ^Ra1 , ^Ra2 , and ^Ra3 in formula (1) can be cited. The alkyl group in ^Ra02 , ^Ra03 , and ^Ra04 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group. The alkyl group in ^Ra6 and ^Ra7 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, or a t-butyl group, and even more preferably an ethyl group, an isopropyl ^group , or a t-butyl group. The alkenyl group in ^Ra6 and ^Ra7 is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably a vinyl group, a propenyl group, an isopropenyl group, or a butenyl group. The alicyclic alkyl group in Ra02, ^Ra03 , ^Ra04 , ^Ra6 , and ^Ra7 preferably has 5 to 12 carbon atoms, more preferably 5 to 10 carbon atoms. The aromatic alkyl group in ^Ra02 , ^Ra03 , ^Ra04 , ^Ra6 , and ^Ra7 preferably has 6 to 12 carbon atoms, more preferably 6 to 10 carbon atoms. In the case of a group formed by combining an alkyl group with an alicyclic alkyl group, the total carbon number of the combined alkyl group and the alicyclic alkyl group is preferably 18 or less. In the case of a group formed by combining an alkyl group with an aromatic alkyl group, the total carbon number of the combined alkyl group and the aromatic alkyl group is preferably 18 or less. R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms or an aromatic alkyl group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a phenyl group, or a naphthyl group. R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic alkyl group having 5 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group. R ^a6 and R ^a7 are each independently preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a vinyl group, a phenyl group, or a naphthyl group, and even more preferably an ethyl group, an isopropyl group, a t-butyl group, a vinyl group, or a phenyl group. m1 is preferably an integer from 0 to 3, more preferably 0 or 1. n1 is preferably an integer from 0 to 3, more preferably 0 or 1. n1' is preferably 0 or 1.

Examples of the structural unit (a1-0) include a structural unit represented by any one of formulas (a1-0-1) to (a1-0-18) and a structural unit in which the methyl group corresponding to R ^a01 in the structural unit (a1-0) is replaced by a hydrogen atom. Preferred structural units are those represented by any one of formulas (a1-0-1) to (a1-0-10), (a1-0-13), and (a1-0-14).

Examples of the structural unit (a1-1) include structural units derived from monomers described in Japanese Patent Application Laid-Open No. 2010-204646. Preferred among these are structural units represented by any one of Formulas (a1-1-1) to (a1-1-7) and structural units in which the methyl group corresponding to R ^a4 in the structural unit (a1-1) is substituted with a hydrogen atom. More preferred are structural units represented by any one of Formulas (a1-1-1) to (a1-1-4).

As the structural unit (a1-2), there can be cited a structural unit represented by any one of formulas (a1-2-1) to (a1-2-12) and a structural unit in which the methyl group corresponding to R ^a5 in the structural unit (a1-2) is replaced by a hydrogen atom. Preferred structural units are those represented by any one of formulas (a1-2-2), (a1-2-5), (a1-2-6), and (a1-2-10) to (a1-2-12).

When the resin (A) includes the structural unit (a1-0), the content thereof is typically 5 mol% to 80 mol%, preferably 5 mol% to 75 mol%, and more preferably 10 mol% to 70 mol%, relative to all structural units in the resin (A). When the resin (A) includes the structural unit (a1-1) and/or the structural unit (a1-2), the total content thereof is typically 10 mol% to 90 mol%, preferably 15 mol% to 85 mol%, more preferably 20 mol% to 80 mol%, further preferably 20 mol% to 75 mol%, and further preferably 20 mol% to 70 mol%, relative to all structural units in the resin (A).

As a structural unit having the group (2) in the structural unit (a1), a structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)") can be cited. [In formula (a1-4), R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R ^a33 represents a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A ^a30 represents a single bond or *-X ^a31 -(A ^a32 -X ^a32 ) _nc -, where * represents the bonding site to the carbon atom to which -R ^a32 is bonded. A ^a32 represents an alkanediyl group having 1 to 6 carbon atoms. X ^a31 and X ^a32 each independently represent -O-, -CO-O-, or -O-CO-. nc represents 0 or 1. la represents any integer from 0 to 4. When la is any integer greater than 2, multiple R ^a33 may be the same or different. R ^a34 and R ^a35 each independently represent a hydrogen atom or a alkyl group having 1 to 12 carbon atoms, and R ^a36 represents a alkyl group having 1 to 20 carbon atoms. Alternatively, R ^a35 and R ^a36 are bonded to each other and, together with the bonded -CO-, form a divalent alkyl group having 2 to 20 carbon atoms. The alkyl group and the -CH ₂ - contained in the divalent alkyl group may be substituted with -O- or -S-.

Examples of the halogen atom in R ^a32 and R ^a33 include fluorine, chlorine, and bromine atoms. Examples of the C 1-6 alkyl group optionally containing a halogen atom in R ^a32 include trifluoromethyl, difluoromethyl, methyl, perfluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, ethyl, perfluoropropyl, 2,2,3,3,3-pentafluoropropyl, propyl, perfluorobutyl, 1,1,2,2,3,3,4,4-octafluorobutyl, butyl, perfluoropentyl, 2,2,3,3,4,4,5,5,5-nonafluoropentyl, pentyl, hexyl, and perfluorohexyl. R ^a32 is preferably a hydrogen atom or a C 1-4 alkyl group, more preferably a hydrogen atom, methyl, or ethyl, and even more preferably a hydrogen atom or methyl. Examples of the alkyl group in R ^a33 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, and hexyl. Examples of the alkoxy group in R ^a33 include methoxy, ethoxy, propoxy, isopropyl, butoxy, sec-butoxy, tert-butoxy, pentyl, and hexyl. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group. Examples of the alkoxyalkyl group in R ^a33 include methoxymethyl, ethoxyethyl, propoxymethyl, isopropyloxymethyl, butoxymethyl, sec-butoxymethyl, and tert-butoxymethyl. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. Examples of the alkoxyalkoxy group in R ^a33 include methoxymethoxy, methoxyethoxy, ethoxymethoxy, ethoxyethoxy, propoxymethoxy, isopropoxymethoxy, butoxymethoxy, sec-butoxymethoxy, and tert-butoxymethoxy. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably methoxyethoxy or ethoxyethoxy. Examples of the alkylcarbonyl group in R ^a33 include acetyl, propionyl, and butyryl. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably acetyl. Examples of the alkylcarbonyloxy group in R ^a33 include acetyloxy, propionyloxy, and butyryloxy. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably acetyloxy. R ^a33 is preferably a halogen atom, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxyl group, a methyl group, a methoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, further preferably a fluorine atom, an iodine atom, a hydroxyl group, a methyl group, a methoxy group, or an ethoxyethoxy group.

Examples of *-X ^a31 -(A ^a32 -X ^a32 ) _nc - include *-O-, *-CO-O-, *-O-CO-, *-CO-OA ^a32 -CO-O-, *-O-CO-A ^a32 -O-, *-OA ^a32 -CO-O-, *-CO-OA ^a32 -O-CO-, and *-O-CO-A ^a32 -O-CO-. Among them, *-CO-O-, *-CO-OA ^a32 -CO-O-, or *-OA ^a32 -CO-O- is preferred.

Examples of the alkanediyl group include methylene, ethylidene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl. A ^a32 is preferably a methylene group or an ethylidene group.

A ^a30 is preferably a single bond, *-CO-O-, or *-CO-OA ^a32 -CO-O-, more preferably a single bond, *-CO-O-, or *-CO-O-CH ₂ -CO-O-, further preferably a single bond or *-CO-O-.

la is preferably 0, 1, or 2, more preferably 0 or 1, and even more preferably 0. Examples of the alkyl group in R ^a34 , R ^a35 , and R ^a36 include alkyl groups, alicyclic alkyl groups, aromatic alkyl groups, and combinations thereof. Examples of the alkyl group include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl groups. The alicyclic alkyl group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic alkyl group include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of the polycyclic alicyclic alkyl group include decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates a bonding site). Examples of aromatic alkyl groups include aryl groups such as phenyl, naphthyl, anthracenyl, biphenyl, and phenanthrenyl. Examples of combined groups include groups formed by combining the aforementioned alkyl groups with alicyclic alkyl groups (e.g., alkylcycloalkyl or cycloalkylalkyl groups such as methylcyclohexyl, dimethylcyclohexyl, methylnorbornyl, cyclohexylmethyl, adamantylmethyl, adamantyldimethyl, and norbornylethyl); aralkyl groups such as benzyl; aromatic alkyl groups having an alkyl group (e.g., p-methylphenyl, p-tert-butylphenyl, tolyl, xylyl, cumenyl, mesityl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl); aromatic alkyl groups having an alicyclic alkyl group (e.g., p-cyclohexylphenyl and p-adamantylphenyl); and aryl-cycloalkyl groups such as phenylcyclohexyl. Particularly, examples of R ^a36 include an alkyl group having 1 to 18 carbon atoms, an alicyclic alkyl group having 3 to 18 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, and a group formed by combining these.

R ^a34 is preferably a hydrogen atom. R ^a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic alkyl group having 3 to 12 carbon atoms, more preferably a methyl group or an ethyl group. The alkyl group in R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic alkyl group having 3 to 18 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, or a group formed by combining these groups, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic alkyl group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and alicyclic alkyl group in ^{R a36} are preferably unsubstituted. The aromatic alkyl group in ^{R a36} is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms. -OC(R ^a34 )(R ^a35 )-OR ^a36 in structural unit (a1-4) dissociates upon contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxyl group. -OC(R ^a34 )(R ^a35 )-OR ^a36 is preferably bonded to the ortho or para position of the benzene ring, more preferably the para position.

Examples of the structural unit (a1-4) include structural units derived from monomers described in Japanese Patent Application Laid-Open No. 2010-204646. Preferred structural units include those represented by Formulas (a1-4-1) to (a1-4-18), and those in which a hydrogen atom corresponding to R ^a32 is replaced by a methyl group. More preferred structural units include those represented by Formulas (a1-4-1) to (a1-4-5), (a1-4-10), (a1-4-13), and (a1-4-14).

When the resin (A) contains the structural unit (a1-4), the content thereof is preferably 3 mol% to 80 mol%, more preferably 5 mol% to 75 mol%, further preferably 7 mol% to 70 mol%, further preferably 7 mol% to 65 mol%, and particularly preferably 10 mol% to 60 mol%, relative to the total of all the structural units in the resin (A).

As the structural unit derived from the (meth)acrylic monomer having the group (2), there can also be mentioned the structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). In formula (a1-5), ^Ra8 represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom, or a halogen atom, which may have a halogen atom. ^Za1 represents a single bond or *-( _CH2 ) _h3 -CO- ^L54- , where h3 represents an integer from 1 to 4, and * represents the bonding site with ^L51 . ^L51 , ^L52 , ^L53 , and ^L54 each independently represent -O- or -S-. S1 represents an integer from 1 to 3. S1' represents an integer from 0 to 3.

Examples of the halogen atom include fluorine and chlorine atoms, with fluorine being preferred. Examples of the C1-6 alkyl group that may have a halogen atom include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, fluoromethyl, and trifluoromethyl. In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group. L ⁵¹ is preferably an oxygen atom. Of L ⁵² and L ⁵³ , one is preferably -O- and the other is -S-. s1 is preferably 1. s1' is preferably an integer from 0 to 2. Z ^a1 is preferably a single bond or *-CH ₂ -CO-O-.

Examples of structural unit (a1-5) include structural units derived from monomers described in Japanese Patent Application Laid-Open No. 2010-61117. Among these, structural units represented by Formulas (a1-5-1) to (a1-5-4) are preferred, and structural units represented by Formula (a1-5-1) or (a1-5-2) are more preferred.

When the resin (A) contains the structural unit (a1-5), the content thereof is preferably 1 mol% to 50 mol%, more preferably 3 mol% to 45 mol%, further preferably 5 mol% to 40 mol%, and further preferably 5 mol% to 30 mol%, relative to all the structural units in the resin (A).

In addition, the following structural units can also be listed as structural units (a1).

When the resin (A) contains structural units such as (a1-3-1) to (a1-3-7), the content of the structural units relative to all the structural units in the resin (A) is preferably 10 mol% to 95 mol%, more preferably 15 mol% to 90 mol%, further preferably 20 mol% to 85 mol%, further preferably 20 mol% to 70 mol%, and particularly preferably 20 mol% to 60 mol%.

In addition, the following structural units can also be listed as structural units (a1). When the resin (A) contains structural units such as (a1-6-1) to (a1-6-3), the content of the structural units relative to all the structural units in the resin (A) is preferably 10 mol% to 60 mol%, more preferably 15 mol% to 55 mol%, further preferably 20 mol% to 50 mol%, further preferably 20 mol% to 45 mol%, and particularly preferably 20 mol% to 40 mol%.

<Structural Unit (s)> Structural unit (s) is derived from a monomer having no acid-labile group (hereinafter sometimes referred to as "monomer (s)"). Monomers having no acid-labile group that are known in the field of anti-etching agents can be used as the monomer from which structural unit (s) is derived. Structural unit (s) preferably has a hydroxyl group or a lactone ring. When a resin containing a structural unit having a hydroxyl group and no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and/or a structural unit having a lactone ring and no acid-labile group (hereinafter sometimes referred to as "structural unit (a3)") is used in the anti-etching composition of the present invention, the resolution of the anti-etching pattern and the adhesion to the substrate can be improved.

<Structural Unit (a2)> The hydroxyl group in the structural unit (a2) may be an alcoholic hydroxyl group or a phenolic hydroxyl group. When a resist pattern is produced from the resist composition of the present invention, when using high-energy radiation such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) as an exposure light source, the structural unit (a2) is preferably a structural unit (a2) having a phenolic hydroxyl group, and more preferably, the structural unit (a2-A) described below is used. Furthermore, when using an ArF excimer laser (193 nm), the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxyl group, and more preferably, the structural unit (a2-1) described below is used. The structural unit (a2) may include one type alone or two or more types.

Examples of the structural unit having a phenolic hydroxyl group in the structural unit (a2) include the structural unit represented by formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)"). [In formula (a2-A), R ^a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R ^a51 represents a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A ^a50 represents a single bond or *-X ^a51 -(A ^a52 -X ^a52 ) _nb -, where * represents the bonding position to the carbon atom to which -R ^a50 is bonded. A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms. X ^a51 and X ^a52 each independently represent -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents any integer from 0 to 4. When mb is any integer greater than 2, multiple R ^a51s may be the same as or different from each other.]

Examples of the halogen atom in R ^a50 and R ^a51 include fluorine, chlorine, and bromine atoms. Examples of the C 1-6 alkyl group optionally containing a halogen atom in R ^a50 include trifluoromethyl, difluoromethyl, methyl, perfluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, ethyl, perfluoropropyl, 2,2,3,3,3-pentafluoropropyl, propyl, perfluorobutyl, 1,1,2,2,3,3,4,4-octafluorobutyl, butyl, perfluoropentyl, 2,2,3,3,4,4,5,5,5-nonafluoropentyl, pentyl, hexyl, and perfluorohexyl. R ^a50 is preferably a hydrogen atom or a C 1-4 alkyl group, more preferably a hydrogen atom, methyl, or ethyl, and even more preferably a hydrogen atom or methyl. Examples of the alkyl group in R ^a51 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, and hexyl. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group. Examples of the alkoxy group in R ^a51 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, and tert-butoxy. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group. Examples of the alkoxyalkyl group in R ^a51 include methoxymethyl, ethoxyethyl, propoxymethyl, isopropoxymethyl, butoxymethyl, sec-butoxymethyl, and tert-butoxymethyl. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. Examples of the alkoxyalkoxy group in R ^a51 include methoxymethoxy, methoxyethoxy, ethoxymethoxy, ethoxyethoxy, propoxymethoxy, isopropoxymethoxy, butoxymethoxy, sec-butoxymethoxy, and tert-butoxymethoxy. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably methoxyethoxy or ethoxyethoxy. Examples of the alkylcarbonyl group in R ^a51 include acetyl, propionyl, and butyryl. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably acetyl. Examples of the alkylcarbonyloxy group in R ^a51 include acetyloxy, propionyloxy, and butyryloxy. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably acetyloxy. R ^a51 is preferably a halogen atom, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxyl group, a methyl group, a methoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, further preferably a fluorine atom, an iodine atom, a hydroxyl group, a methyl group, a methoxy group, or an ethoxyethoxy group.

Examples of *-X ^a51 -(A ^a52 -X ^a52 ) _nb - include: *-O-, *-CO-O-, *-O-CO-, *-CO-OA ^a52 -CO-O-, *-O-CO-A ^a52 -O-, *-OA ^a52 -CO-O-, *-CO-OA ^a52 -O-CO-, *-O-CO-A ^a52 -O-CO-. Among them, *-CO-O-, *-CO-OA ^a52 -CO-O-, or *-OA ^a52 -CO-O- are preferred.

Examples of the alkanediyl group include methylene, ethylidene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl. A ^a52 is preferably a methylene group or an ethylidene group.

A ^a50 is preferably a single bond, *-CO-O-, or *-CO-OA ^a52 -CO-O-, more preferably a single bond, *-CO-O-, or *-CO-O-CH ₂ -CO-O-, further preferably a single bond or *-CO-O-.

mb is preferably 0, 1, or 2, more preferably 0 or 1, and even more preferably 0. The hydroxyl group is preferably bonded to the ortho or para position of the benzene ring, more preferably to the para position.

Examples of the structural unit (a2-A) include structural units derived from monomers described in Japanese Patent Application Publication No. 2010-204634 and Japanese Patent Application Publication No. 2012-12577. Examples of the structural unit (a2-A) include structural units represented by formulas (a2-2-1) to (a2-2-16), and structural units represented by formulas (a2-2-1) to (a2-2-16) in which the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom. The structural unit (a2-A) is preferably a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), a structural unit represented by formula (a2-2-12) to formula (a2-2-14), and a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), a structural unit represented by formula (a2-2-12) to formula (a2-2-14) which is equivalent to R in the structural unit (a2-A). The methyl group of ^a50 is replaced by a hydrogen atom, and more preferably the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-8), the structural unit represented by formula (a2-2-12) to the structural unit represented by formula (a2-2-14), and the structural unit represented by formula (a2-2-3), or the structural unit represented by formula (a2-2-8), the structural unit represented by formula (a2-2-12) to the structural unit represented by formula (a2-2-14) which is equivalent to R in the structural unit (a2-A). The methyl group of ^a50 is replaced by a hydrogen atom, and more preferably the structural unit represented by formula (a2-2-8) and the structural unit represented by formula (a2-2-8) which is equivalent to R in the structural unit (a2-A). The methyl group of ^a50 is replaced by a hydrogen atom.

When the structural unit (a2-A) is included in the resin (A), the content of the structural unit (a2-A) relative to all the structural units is preferably 5 mol% to 80 mol%, more preferably 10 mol% to 70 mol%, further preferably 15 mol% to 65 mol%, and further preferably 20 mol% to 65 mol%. The structural unit (a2-A) can be incorporated into the resin (A), for example, by polymerizing the structural unit (a1-4) and then treating the resin with an acid such as p-toluenesulfonic acid. Alternatively, the structural unit (a2-A) can be incorporated into the resin (A) by polymerizing an ester such as acetoxystyrene and then treating the resin with an alkali such as tetramethylammonium hydroxide.

Examples of the structural unit having an alcoholic hydroxyl group in the structural unit (a2) include the structural unit represented by formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)"). In formula (a2-1), L ^a3 represents -O- or *-O-(CH ₂ ) _k2 -CO-O-, k2 represents any integer from 1 to 7. * represents the bonding site with -CO-. R ^a14 represents a hydrogen atom or a methyl group. R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group, or a hydroxyl group. o1 represents any integer from 0 to 10.

In formula (a2-1), L ^a3 is preferably -O-, -O-(CH ₂ ) _f1 -CO-O- (where f1 represents an integer from 1 to 4), and more preferably -O-. R ^a14 is preferably a methyl group. R ^a15 is preferably a hydrogen atom. R ^a16 is preferably a hydrogen atom or a hydroxyl group. o1 is preferably an integer from 0 to 3, and more preferably 0 or 1.

Examples of structural unit (a2-1) include structural units derived from monomers described in Japanese Patent Application Laid-Open No. 2010-204646. Preferred are structural units represented by any one of Formulas (a2-1-1) to (a2-1-6), more preferably by any one of Formulas (a2-1-1) to (a2-1-4), and even more preferably by Formulas (a2-1-1) or (a2-1-3).

When the resin (A) contains the structural unit (a2-1), its content relative to all the structural units in the resin (A) is generally 1 mol% to 45 mol%, preferably 1 mol% to 40 mol%, more preferably 1 mol% to 35 mol%, further preferably 1 mol% to 20 mol%, and even more preferably 1 mol% to 10 mol%.

<Structural Unit (a3)> The lactone ring in structural unit (a3) may be a single ring such as β-propiolactone, γ-butyrolactone, or δ-valerolactone, or may be a fused ring of a single lactone ring and another ring. Preferred examples include a γ-butyrolactone ring, an adamantanolactone ring, or a bridged ring containing a γ-butyrolactone ring structure (e.g., the structural unit represented by formula (a3-2) below).

The structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3), or formula (a3-4). These structural units may be present alone or in combination of two or more. [In formula (a3-1), formula (a3-2), formula (a3-3), and formula (a3-4), L ^a4 , L ^a5 , and L ^a6 each independently represent a group represented by -O- or *-O-(CH ₂ ) _k3 -CO-O- (k3 represents any integer from 1 to 7). L ^a7 represents -O-, *-OL ^a8 -O-, *-OL ^{a8 -CO-O-, *-OL a8} -CO-OL ^a9 -CO-O-, or *-OL ^{a8 -O} -CO-L ^a9 -O-. L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding position to the carbonyl group. R ^a18 , R ^a19 , and R ^a20 each independently represent a hydrogen atom or a methyl group. R ^a24 represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom, or a halogen atom which may have a halogen atom. ^Xa3 represents _-CH2- or an oxygen atom. ^Ra21 represents an aliphatic alkyl group having 1 to 4 carbon atoms. ^Ra22 , ^Ra23 , and ^Ra25 each independently represent a carboxyl group, a cyano group, or an aliphatic alkyl group having 1 to 4 carbon atoms. p1 represents any integer from 0 to 5. q1 represents any integer from 0 to 3. r1 represents any integer from 0 to 3. w1 represents any integer from 0 to 8. When p1, q1, r1, and/or w1 are 2 or more, multiple ^Ra21 , ^Ra22 , ^Ra23 , and/or ^Ra25 may be the same or different.

Examples of the aliphatic alkyl group in R ^a21 , R ^a22 , R ^a23 , and R ^a25 include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, and tert-butyl. Examples of the halogen atom in R ^a24 include fluorine, chlorine, bromine, and iodine. Examples of the alkyl group in R ^a24 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, and hexyl. Examples of the alkyl group include alkyl groups having 1 to 4 carbon atoms, and more preferably, methyl or ethyl. Examples of the alkyl group having a halogen atom in R ^a24 include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluoro-sec-butyl, perfluoro-tert-butyl, perfluoropentyl, perfluorohexyl, trichloromethyl, tribromomethyl, and triiodomethyl.

Examples of the alkanediyl group in ^La8 and ^La9 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group.

In formulas (a3-1) to (a3-3), ^La4 to ^La6 are each independently preferably -O- or *-O-( _CH2 ) _k3 -CO-O-, where k3 is an integer from 1 to 4, more preferably -O- and *-O- _CH2 -CO-O-, and further preferably an oxygen atom. ^Ra18 to ^Ra21 are each preferably a methyl group. ^Ra22 and ^Ra23 are each independently preferably a carboxyl group, a cyano group, or a methyl group. P1, Q1, and R1 are each independently preferably an integer from 0 to 2, more preferably 0 or 1.

In formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R ^a25 is preferably a carboxyl group, a cyano group, or a methyl group. L ^a7 is preferably -O- or *-OL ^a8 -CO-O-, more preferably -O-, -O-CH ₂ -CO-O-, or -OC ₂ H ₄ -CO-O-. w1 is preferably an integer from 0 to 2, more preferably 0 or 1. In particular, formula (a3-4) is preferably formula (a3-4)'. (wherein, ^Ra24 and ^La7 have the same meanings as described above)

Examples of the structural unit (a3) include structural units derived from monomers described in Japanese Patent Application Laid-Open No. 2010-204646, monomers described in Japanese Patent Application Laid-Open No. 2000-122294, and monomers described in Japanese Patent Application Laid-Open No. 2012-41274. Preferred structural units (a3) include structural units represented by any one of formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-1), formula (a3-3-2), and formulas (a3-4-1) to (a3-4-12), and structural units in which the methyl groups corresponding to R ^a18 , R ^a19 , R ^a20 , and R ^a24 in formulas (a3-1) to (a3-4) are substituted with hydrogen atoms.

When the resin (A) includes the structural unit (a3), the total content thereof relative to all structural units in the resin (A) is generally 5 mol% to 70 mol%, preferably 10 mol% to 65 mol%, and more preferably 10 mol% to 60 mol%. Also, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), or the structural unit (a3-4) relative to all structural units in the resin (A) is preferably 5 mol% to 60 mol%, more preferably 5 mol% to 50 mol%, and even more preferably 10 mol% to 50 mol%.

〈Structural unit (a4)〉 As structural unit (a4), the following structural units can be listed. [In formula (a4), R ⁴¹ represents a hydrogen atom or a methyl group. R ⁴² represents a halogen-containing saturated alkyl group having 1 to 24 carbon atoms, wherein -CH ₂ - in the saturated alkyl group may be substituted with -O- or -CO.] Examples of the saturated alkyl group represented by R ⁴² include chain saturated alkyl groups, monocyclic or polycyclic alicyclic saturated alkyl groups, and groups formed by combining these groups.

Examples of chain saturated alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl. Examples of monocyclic or polycyclic alicyclic saturated alkyl groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; and polycyclic alicyclic saturated alkyl groups such as decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates a bonding site). Examples of groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated alkyl groups, such as -alkanediyl-alicyclic saturated alkyl, -alicyclic saturated alkyl-alkyl, and -alkanediyl-alicyclic saturated alkyl-alkyl.

Examples of the structural unit (a4) include the structural unit represented by formula (a4-0), the structural unit represented by formula (a4-1), and the structural unit represented by formula (a4-4). [In formula (a4-0), R ⁵⁴ represents a hydrogen atom or a methyl group. L ^4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. L ^3a represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms. R ⁶⁴ represents a hydrogen atom or a fluorine atom.]

Examples of the alkanediyl group in L ^4a include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, and butane-1,4-diyl; and branched alkanediyl groups such as ethane-1,1-diyl, propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, and 2-methylpropane-1,2-diyl.

Examples of the perfluoroalkanediyl group in L ^3a include difluoromethylene, perfluoroethylene, perfluoroethylfluoromethylene, perfluoropropane-1,3-diyl, perfluoropropane-1,2-diyl, perfluoropropane-2,2-diyl, perfluorobutane-1,4-diyl, perfluorobutane-2,2-diyl, perfluorobutane-1,2-diyl, perfluoropentane-1,5-diyl, perfluoropentane-2,2-diyl, perfluoropentane-3, The perfluorocycloalkanediyl group in L 3a includes perfluorocyclohexanediyl, perfluorocyclopentanediyl, perfluorocycloheptanediyl ^, and perfluoroadamantanediyl.

^L4a is preferably a single bond, methylene or ethylene, more preferably a single bond or methylene. ^L3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

Examples of the structural unit (a4-0) include the structural units shown below and structural units in which the methyl group corresponding to R ⁵⁴ in the structural unit (a4-0) is replaced with a hydrogen atom among the structural units below.

[In formula (a4-1), R ^a41 represents a hydrogen atom or a methyl group. R ^a42 represents a saturated alkyl group having 1 to 20 carbon atoms which may have a substituent, wherein -CH ₂ - in the saturated alkyl group may be substituted with -O- or -CO-. A ^a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent, or a group represented by formula (a-g1). At least one of A ^a41 and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent. [In formula (a-g1), s represents 0 or 1. ^Aa42 and ^Aa44 each independently represent a divalent saturated alkyl group having 1 to 5 carbon atoms which may have a substituent. ^Aa43 represents a single bond or a divalent saturated alkyl group having 1 to 5 carbon atoms which may have a substituent. ^Xa41 and ^Xa42 each independently represent -O-, -CO-, -CO-O-, or -O-CO-. The total number of carbon atoms in ^Aa42 , ^Aa43 , ^Aa44 , ^Xa41 , and ^Xa42 is 7 or less.] * represents a bonding site, and the * on the right side represents a bonding site with -O-CO- ^Ra42 .]

Examples of the saturated alkyl group in R ^a42 include chain alkyl groups, monocyclic or polycyclic saturated alicyclic alkyl groups, and groups formed by combining these groups.

Examples of chain alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl. Examples of monocyclic or polycyclic saturated alicyclic alkyl groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; and polycyclic alicyclic alkyl groups such as decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates a bonding site). Examples of groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more saturated alicyclic alkyl groups, such as -alkanediyl-saturated alicyclic alkyl group, -saturated alicyclic alkyl group-alkyl group, and -alkanediyl-saturated alicyclic alkyl group-alkyl group.

Examples of the substituents possessed by R ^a42 include at least one selected from the group consisting of a halogen atom and a group represented by formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. [In formula (a-g3), ^Xa43 represents an oxygen atom, a carbonyl group, *-O-CO-, or *-CO-O-. ^Aa45 represents a saturated alkyl group having 1 to 17 carbon atoms which may have a halogen atom. * represents the bonding site with ^Ra42 .] In the formula ^Ra42 - ^Xa43 - ^Aa45 , when ^Ra42 does not have a halogen atom, ^Aa45 represents a saturated alkyl group having 1 to 17 carbon atoms which has at least one halogen atom.

Examples of the saturated alkyl group in ^Aa45 include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl; monocyclic alicyclic alkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; and polycyclic alicyclic alkyl groups such as decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates a bonding site). Examples of groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic alkyl groups, such as -alkanediyl-alicyclic alkyl, -alicyclic alkyl-alkyl, and -alkanediyl-alicyclic alkyl-alkyl.

R ^a42 is preferably a saturated alkyl group optionally containing a halogen atom, more preferably an alkyl group containing a halogen atom and/or a saturated alkyl group containing a group represented by formula (a-g3). When R ^a42 is a saturated alkyl group containing a halogen atom, it is preferably a saturated alkyl group containing a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, further preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of perfluoroalkyl groups include perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl, and perfluorooctyl. Examples of perfluorocycloalkyl groups include perfluorocyclohexyl. When R ^a42 is a saturated alkyl group having a group represented by formula (a-g3), the total number of carbon atoms in R ^a42 , including the number of carbon atoms contained in the group represented by formula (a-g3), is preferably 15 or less, more preferably 12 or less. When a substituent has a group represented by formula (a-g3), the number of substituents is preferably one.

When R ^a42 is a saturated alkyl group having a group represented by formula (a-g3), R ^a42 is further preferably a group represented by formula (a-g2). [In formula (a-g2), ^Aa46 represents a divalent saturated alkyl group having 1 to 17 carbon atoms that may have a halogen atom. ^Xa44 represents **-O-CO- or **-CO-O- (** represents the bonding site with ^Aa46 ). ^Aa47 represents a saturated alkyl group having 1 to 17 carbon atoms that may have a halogen atom. The total number of carbon atoms in ^Aa46 , ^Aa47 , and ^Xa44 is 18 or less, and at least one of ^Aa46 and ^Aa47 has at least one halogen atom. * represents the bonding site with the carbonyl group.]

The carbon number of the saturated alkyl group of A ^a46 is preferably 1 to 6, more preferably 1 to 3. The carbon number of the saturated alkyl group of A ^a47 is preferably 4 to 15, more preferably 5 to 12. A ^a47 is further preferably a cyclohexyl group or an adamantyl group.

A preferred structure of the group represented by formula (a-g2) is the following structure (* represents the bonding site with the carbonyl group).

Examples of the alkanediyl group in ^Aa41 include linear alkanediyl groups such as methylene, ethylidene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl; and branched alkanediyl groups such as propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,2-diyl, 1-methylbutane-1,4-diyl, and 2-methylbutane-1,4-diyl. Examples of substituents in the alkanediyl group represented by ^Aa41 include hydroxyl and alkoxy groups having 1 to 6 carbon atoms. ^Aa41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and even more preferably an ethylidene group.

Examples of the divalent saturated alkyl group represented by ^Aa42 , ^Aa43 , and ^Aa44 in the group represented by formula (a-g1) include linear or branched alkanediyl groups, monocyclic divalent alicyclic saturated alkyl groups, and divalent saturated alkyl groups formed by combining alkanediyl groups and divalent alicyclic saturated alkyl groups. Specific examples include methylene, ethylidene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, 1-methylpropane-1,3-diyl, 2-methylpropane-1,3-diyl, and 2-methylpropane-1,2-diyl. Examples of the substituent for the divalent saturated alkyl group represented by ^Aa42 , ^Aa43 , and ^Aa44 include a hydroxyl group and an alkoxy group having 1 to 6 carbon atoms. s is preferably 0.

Among the groups represented by formula (a-g1), the following groups can be cited as groups where X ^a42 is -O-, -CO-, -CO-O-, or -O-CO-. In the following examples, * and ** each represent a bonding site, and ** represents a bonding site with -O-CO-R ^a42 .

Examples of the structural unit represented by formula (a4-1) include the structural units shown below and structural units in which the methyl group corresponding to R ^a41 in the structural unit represented by formula (a4-1) is substituted with a hydrogen atom.

Examples of the structural unit represented by formula (a4-1) include the structural unit represented by formula (a4-2) and the structural unit represented by formula (a4-3). [In formula (a4-2), ^Rf5 represents a hydrogen atom or a methyl group. ^L44 represents an alkanediyl group having 1 to 6 carbon atoms, wherein _-CH2- in the alkanediyl group may be substituted with -O- or -CO-. ^Rf6 represents a saturated alkyl group having 1 to 20 carbon atoms and containing a fluorine atom. The upper limit of the total carbon number of ^L44 and ^Rf6 is 21.]

Examples of the alkanediyl group having 1 to 6 carbon atoms in L ⁴⁴ include the same groups as those exemplified in A ^a41 . Examples of the saturated alkyl group in R ^f6 include the same groups as those exemplified in R ^42. The alkanediyl group in L ⁴⁴ is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.

Examples of the structural unit represented by formula (a4-2) include the structural units represented by formulas (a4-1-1) to (a4-1-11). A structural unit represented by formula (a4-2) may also include a structural unit in which the methyl group corresponding to R ^f5 in structural unit (a4-2) is substituted with a hydrogen atom.

[In formula (a4-3), ^Rf7 represents a hydrogen atom or a methyl group. ^L5 represents an alkanediyl group having 1 to 6 carbon atoms. ^Af13 represents a divalent saturated alkyl group having 1 to 18 carbon atoms that may have a fluorine atom. ^Xf12 represents *-O-CO- or *-CO-O- (* represents the bonding site with ^Af13 ). ^Af14 represents a saturated alkyl group having 1 to 17 carbon atoms that may have a fluorine atom. At least one of ^Af13 and ^Af14 contains a fluorine atom, and the upper limit of the total number of carbon atoms in ^L5 , ^Af13 , and ^Af14 is 20.]

As the alkanediyl group in L ⁵ , the same groups as exemplified for the alkanediyl group in A ^a41 can be mentioned.

The divalent saturated alkyl group optionally having a fluorine atom in A ^f13 is preferably a divalent chain saturated alkyl group optionally having a fluorine atom or a divalent alicyclic saturated alkyl group optionally having a fluorine atom, and more preferably a perfluoroalkanediyl group. Examples of the divalent chain saturated alkyl group optionally having a fluorine atom include alkanediyl groups such as methylene, ethylidene, propylene, butanediyl, and pentanediyl; and perfluoroalkanediyl groups such as difluoromethylene, perfluoroethylidene, perfluoropropylene, perfluorobutanediyl, and perfluoropentanediyl. The divalent alicyclic saturated alkyl group optionally having a fluorine atom may be monocyclic or polycyclic. Examples of monocyclic groups include cyclohexanediyl and perfluorocyclohexanediyl. Examples of the polycyclic group include adamantanediyl, norbornanediyl, and perfluoroadamantanediyl.

The saturated alkyl group and the saturated alkyl group which may have a fluorine atom in A ^f14 may be the same as those exemplified in R ^a42 . Among them, preferred are trifluoromethyl, difluoromethyl, methyl, perfluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, ethyl, perfluoropropyl, 2,2,3,3,3-pentafluoropropyl, propyl, perfluorobutyl, 1,1,2,2,3,3,4,4-octafluorobutyl, butyl, perfluoropentyl, 2,2,3,3,4,4, Fluorinated alkyl groups such as 5,5,5-nonafluoropentyl, pentyl, hexyl, perfluorohexyl, heptyl, perfluoroheptyl, octyl, and perfluorooctyl, cyclopropylmethyl, cyclopropyl, cyclobutylmethyl, cyclopentyl, cyclohexyl, perfluorocyclohexyl, adamantyl, adamantylmethyl, adamantyldimethyl, norbornyl, norbornylmethyl, perfluoroadamantyl, and perfluoroadamantylmethyl.

In formula (a4-3), ^L5 is preferably an ethylene group. The divalent saturated alkyl group in ^Af13 is preferably a group consisting of a divalent chain saturated alkyl group having 1 to 6 carbon atoms and a divalent alicyclic saturated alkyl group having 3 to 12 carbon atoms, and more preferably a divalent chain saturated alkyl group having 2 to 3 carbon atoms. The saturated alkyl group in ^Af14 is preferably a group consisting of a chain saturated alkyl group having 3 to 12 carbon atoms and alicyclic saturated alkyl group having 3 to 12 carbon atoms, and more preferably a group consisting of a chain saturated alkyl group having 3 to 10 carbon atoms and alicyclic saturated alkyl group having 3 to 10 carbon atoms. Among them, A ^f14 is preferably a group containing an alicyclic saturated alkyl group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group.

Examples of the structural unit represented by formula (a4-3) include the structural units represented by formulas (a4-1'-1) to (a4-1'-11). A structural unit represented by formula (a4-3) may also include a structural unit in which the methyl group corresponding to R ^f7 in structural unit (a4-3) is substituted with a hydrogen atom.

As the structural unit (a4), the structural unit represented by formula (a4-4) can also be listed. [In formula (a4-4), ^Rf21 represents a hydrogen atom or a methyl group. ^Af21 represents -( _CH2 ) _j1- , -( _CH2 ) _j2 -O-( _CH2 ) _j3- , or -( _CH2 ) _j4 -CO-O-( _CH2 ) _j5- . j1 to j5 each independently represent an integer from 1 to 6. ^Rf22 represents a saturated alkyl group having 1 to 10 carbon atoms and containing a fluorine atom.]

The saturated alkyl group in ^Rf22 may be the same as the saturated alkyl group represented by ^Ra42 . ^Rf22 is preferably a C1-10 alkyl group containing a fluorine atom or a C1-10 alicyclic saturated alkyl group containing a fluorine atom, more preferably a C1-10 alkyl group containing a fluorine atom, and even more preferably a C1-6 alkyl group containing a fluorine atom.

In formula (a4-4), A ^f21 is preferably -(CH ₂ ) _j1 -, more preferably an ethylene group or a methylene group, and further preferably a methylene group.

Examples of the structural unit represented by formula (a4-4) include the following structural unit and a structural unit represented by the following formula in which the methyl group corresponding to R ^f21 in the structural unit (a4-4) is substituted with a hydrogen atom.

When the resin (A) has the structural unit (a4), its content relative to all the structural units of the resin (A) is preferably 1 mol% to 20 mol%, more preferably 2 mol% to 15 mol%, and even more preferably 3 mol% to 10 mol%.

<Structural Unit (a5)> Examples of the non-isolated alkyl group contained in the structural unit (a5) include groups having a linear, branched, or cyclic alkyl group. Among them, the structural unit (a5) is preferably a group having an alicyclic alkyl group. Examples of the structural unit (a5) include the structural unit represented by formula (a5-1). [In formula (a5-1), R ⁵¹ represents a hydrogen atom or a methyl group. R ⁵² represents an alicyclic alkyl group having 3 to 18 carbon atoms, wherein the hydrogen atom contained in the alicyclic alkyl group may be substituted with an aliphatic alkyl group having 1 to 8 carbon atoms. L ⁵⁵ represents a single bond or a divalent saturated alkyl group having 1 to 18 carbon atoms, wherein the -CH ₂ - contained in the saturated alkyl group may be substituted with -O- or -CO-.]

The alicyclic alkyl group in R ⁵² may be either monocyclic or polycyclic. Examples of monocyclic alicyclic alkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Examples of polycyclic alicyclic alkyl groups include adamantyl and norbornyl. Examples of aliphatic alkyl groups having 1 to 8 carbon atoms include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. Examples of alicyclic alkyl groups having a substituent include 3-methyladamantyl. R ⁵² is preferably an unsubstituted alicyclic alkyl group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

Examples of the divalent saturated alkyl group in L ⁵⁵ include divalent chain saturated alkyl groups and divalent alicyclic saturated alkyl groups, with divalent chain saturated alkyl groups being preferred. Examples of the divalent chain saturated alkyl group include methylene, ethylene, propanediyl, butanediyl, and alkanediyl groups such as pentanediyl. The divalent alicyclic saturated alkyl group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated alkyl group include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl and norbornanediyl.

Examples of the group in which -CH ₂ - in the divalent saturated alkyl group represented by L ⁵⁵ is substituted with -O- or -CO- include the groups represented by formulae (L1-1) to (L1-4). In the following formulae, * and ** each represent a bonding site, and * represents a bonding site to an oxygen atom. In formula (L1-1), ^Xx1 represents *-O-CO- or *-CO-O- (* represents the bonding site to ^Lx1 ). ^Lx1 represents a divalent aliphatic saturated alkyl group having 1 to 16 carbon atoms. ^Lx2 represents a single bond or a divalent aliphatic saturated alkyl group having 1 to 15 carbon atoms. The total number of carbon atoms of ^Lx1 and ^Lx2 is 16 or less. In formula (L1-2), ^Lx3 represents a divalent aliphatic saturated alkyl group having 1 to 17 carbon atoms. ^Lx4 represents a single bond or a divalent aliphatic saturated alkyl group having 1 to 16 carbon atoms. The total number of carbon atoms of ^Lx3 and ^Lx4 is 17 or less. In formula (L1-3), ^Lx5 represents a divalent aliphatic saturated alkyl group having 1 to 15 carbon atoms. ^Lx6 and ^Lx7 each independently represent a single bond or a divalent aliphatic saturated alkyl group having 1 to 14 carbon atoms. The total carbon number of ^Lx5 , ^Lx6 , and ^Lx7 is 15 or less. In formula (L1-4), ^Lx8 and ^Lx9 represent a single bond or a divalent aliphatic saturated alkyl group having 1 to 12 carbon atoms. ^Wx1 represents a divalent alicyclic saturated alkyl group having 3 to 15 carbon atoms. The total carbon number of ^Lx8 , ^Lx9 , and ^Wx1 is 15 or less.

^Lx1 is preferably a divalent aliphatic saturated alkyl group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. ^Lx2 is preferably a single bond or a divalent aliphatic saturated alkyl group having 1 to 8 carbon atoms, more preferably a single bond. ^Lx3 is preferably a divalent aliphatic saturated alkyl group having 1 to 8 carbon atoms. ^Lx4 is preferably a single bond or a divalent aliphatic saturated alkyl group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. ^Lx6 is preferably a single bond or a divalent aliphatic saturated alkyl group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. ^Lx7 is preferably a single bond or a divalent aliphatic saturated alkyl group ^having 1 to 8 carbon atoms. L ^x8 is preferably a single bond or a divalent aliphatic saturated alkyl group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. L ^x9 is preferably a single bond or a divalent aliphatic saturated alkyl group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. W ^x1 is preferably a divalent alicyclic saturated alkyl group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

Examples of the group represented by formula (L1-1) include the following divalent groups.

Examples of the group represented by formula (L1-2) include the following divalent groups.

Examples of the group represented by formula (L1-3) include the following divalent groups.

Examples of the group represented by formula (L1-4) include the following divalent groups.

L ⁵⁵ is preferably a single bond or a group represented by formula (L1-1).

Examples of the structural unit (a5-1) include the structural units shown below and structural units in which the methyl group corresponding to R ⁵¹ in the structural unit (a5-1) is replaced with a hydrogen atom among the structural units below.

When the resin (A) has the structural unit (a5), its content is preferably 1 mol% to 30 mol%, more preferably 2 mol% to 20 mol%, and even more preferably 3 mol% to 15 mol%, relative to all the structural units of the resin (A).

<Structural Unit (II)> Resin (A) may further contain a structural unit that decomposes upon exposure to light to generate an acid (hereinafter sometimes referred to as "structural unit (II)"). Specific examples of structural unit (II) include those described in Japanese Patent Application Laid-Open No. 2016-79235. Preferred structural units include those having a sulfonate or carboxylate group and an organic cation as a side chain, or those having a cobalt group and an organic anion as a side chain.

The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (II-2-A'). [In formula (II-2-A'), X ^III3 represents a divalent saturated alkyl group having 1 to 18 carbon atoms. The -CH ₂ - contained in the saturated alkyl group may be substituted with -O-, -S-, or -CO-. The hydrogen atom contained in the saturated alkyl group may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, or a hydroxyl group. A ^x1 represents an alkanediyl group having 1 to 8 carbon atoms. The hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA ^- represents a sulfonate group or a carboxylate group. R ^III3 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ZA ⁺ represents an organic cation.]

Examples of the halogen atom represented by R ^III3 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the C 1-6 alkyl group optionally having a halogen atom represented by R ^III3 include the same C 1-6 alkyl group optionally having a halogen atom as those represented by R ^a8 . Examples of the alkanediyl group having 1 to 8 carbon atoms represented by ^Ax1 include methylene, ethylidene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl. In A ^x1 , examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluoro-sec-butyl, perfluoro-t-butyl, perfluoropentyl, and perfluorohexyl.

Examples of the divalent saturated alkyl group having 1 to 18 carbon atoms represented by ^XIII3 include linear or branched alkanediyl groups, monocyclic or polycyclic divalent alicyclic saturated alkyl groups, and combinations thereof are also possible. Specifically, the following can be cited: linear alkanediyl groups such as methylene, ethylidene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; and branched alkanediyl groups such as butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; Cycloalkane diyl groups such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl, and divalent monocyclic alicyclic saturated alkyl groups; and norbornane-1,4-diyl, norbornane-2,5-diyl, adamantane-1,5-diyl, and adamantane-2,6-diyl, and other divalent polycyclic alicyclic saturated alkyl groups.

Examples of divalent groups in which -CH ₂ - in a saturated alkyl group is replaced by -O-, -S-, or -CO- include those represented by formulas (X1) to (X53). In each case, the number of carbon atoms in the -CH ₂ - in the saturated alkyl group before being replaced by -O-, -S-, or -CO- is 17 or less. In the following formulae, * and ** represent bonding sites, and * represents the bonding site to A ^x1 .

^X3 represents a divalent saturated alkyl group having 1 to 16 carbon atoms. ^X4 represents a divalent saturated alkyl group having 1 to 15 carbon atoms. ^X5 represents a divalent saturated alkyl group having 1 to 13 carbon atoms. ^X6 represents a divalent saturated alkyl group having 1 to 14 carbon atoms. ^X7 represents a trivalent saturated alkyl group having 1 to 14 carbon atoms. ^X8 represents a divalent saturated alkyl group having 1 to 13 carbon atoms.

Examples of the organic cation represented by ZA ⁺ include organic onium cations, organic zirconia cations, organic iodine cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic zirconia cations and organic iodine cations are preferred, and aryl zirconia cations are more preferred. Specifically, examples include cations represented by any of Formulas (b2-1) to (b2-4) described below (hereinafter sometimes referred to as "cation (b2-1)" etc. according to the formula number).

The structural unit represented by formula (II-2-A') is preferably the structural unit represented by formula (II-2-A). [In formula (II-2-A), R ^III3 , X ^III3 , and ZA ⁺ have the same meanings as described above. z represents any integer from 0 to 6. R ^III2 and R ^III4 each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms. When z is 2 or greater, multiple R ^III2 and R ^III4 may be the same or different. Q ^a and Q ^b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.]

Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by R ^III2 , R ^III4 , Q ^a , and Q ^b include the same perfluoroalkyl group having 1 to 6 carbon atoms represented by Q ^b1 described later.

The structural unit represented by formula (II-2-A) is preferably a structural unit represented by formula (II-2-A-1). [In formula (II-2-A-1), R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b , z, and ZA ⁺ have the same meanings as described above. R ^III5 represents a saturated alkyl group having 1 to 12 carbon atoms. ^XI2 represents a divalent saturated alkyl group having 1 to 11 carbon atoms. -CH ₂ - in the saturated alkyl group may be substituted with -O-, -S-, or -CO-, and the hydrogen atom in the saturated alkyl group may be substituted with a halogen atom or a hydroxyl group.]

Examples of the saturated alkyl group having 1 to 12 carbon atoms represented by R ^III5 include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl. Examples of the divalent saturated alkyl group represented by X ^I2 include the same divalent saturated alkyl groups as those represented by X ^III3 .

The structural unit represented by formula (II-2-A-1) is preferably a structural unit represented by formula (II-2-A-2). [In formula (II-2-A-2), R ^III3 , R ^III5 and ZA ⁺ have the same meanings as described above. m and nA each independently represent 1 or 2.]

Examples of the structural unit represented by formula (II-2-A') include the following structural units, structural units in which the group corresponding to the methyl group R ^III3 is substituted with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or a C1-6 alkyl group optionally containing a halogen atom (e.g., a trifluoromethyl group), and the structural units described in International Publication No. 2012/050015. ZA ⁺ represents an organic cation.

The structural unit having a cobalt group and an organic anion in the side chain is preferably a structural unit represented by formula (II-1-1). [In formula (II-1-1), A ^II1 represents a single bond or a divalent linking group. R ^II1 represents a divalent aromatic alkyl group having 6 to 18 carbon atoms. R ^II2 and R ^II3 each independently represent a alkyl group having 1 to 18 carbon atoms, and R ^II2 and R ^II3 may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. R ^II4 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A ^- represents an organic anion.] Examples of the divalent aromatic alkyl group having 6 to 18 carbon atoms represented by R ^II1 include phenylene and naphthylene. Examples of the alkyl group represented by R ^II2 and R ^II3 include alkyl groups, alicyclic alkyl groups, aromatic alkyl groups, and groups formed by combining these groups. Examples of alkyl and alicyclic alkyl groups include the same as those described above. Examples of aromatic alkyl groups include aryl groups such as phenyl, naphthyl, anthracenyl, biphenyl, and phenanthrenyl. Examples of combined groups include groups combining the above-mentioned alkyl groups with alicyclic alkyl groups, aralkyl groups such as benzyl, aromatic alkyl groups having an alkyl group (such as p-methylphenyl, p-tert-butylphenyl, tolyl, xylyl, cumyl, mesityl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl), aromatic alkyl groups having an alicyclic alkyl group (such as p-cyclohexylphenyl and p-adamantylphenyl), and aryl-cycloalkyl groups such as phenylcyclohexyl. Examples of the halogen atom represented by R ^II4 include fluorine, chlorine, bromine, and iodine. Examples of the C1-6 alkyl group optionally containing a halogen atom represented by R ^II4 include the same ones as the C1-6 alkyl group optionally containing a halogen atom represented by R ^a8 . Examples of the divalent linking group represented by A ^II1 include a C1-18 divalent saturated alkyl group, wherein the -CH ₂ - group contained in the divalent saturated alkyl group may be substituted with -O-, -S-, or -CO-. Specifically, examples include the same ones as the C1-18 divalent saturated alkyl group represented by X ^III3 .

Examples of the structural unit containing a cation in formula (II-1-1) include the structural units shown below, and structural units in which the group corresponding to the methyl group of R ^II4 is substituted with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms (e.g., a trifluoromethyl group) which may have a halogen atom.

Examples of the organic anion represented by ^A- include sulfonate anions, sulfonylimide anions, sulfonylmide anions, and carboxylate anions. The organic anion represented by ^A- is preferably a sulfonate anion. Examples of the sulfonate anion include the same anions as those represented by formula (B1).

Examples of the sulfonylimide anion represented by ^A- include the following.

The following are examples of sulfonyl methide anions.

The following are examples of carboxylate anions.

Examples of the structural unit represented by formula (II-1-1) include the following structural units.

In the resin (A), when the structural unit (II) is contained, the content of the structural unit (II) is preferably 1 mol% to 20 mol%, more preferably 2 mol% to 15 mol%, and even more preferably 3 mol% to 10 mol% relative to all the structural units of the resin (A).

The resin (A) may have structural units other than the above-mentioned structural units, and examples of such structural units include those known in the art.

Resin (A) is preferably a resin comprising structural unit (a1) and structural unit (s), that is, a copolymer of monomer (a1) and monomer (s). Structural unit (a1) is preferably at least one selected from the group consisting of structural unit (a1-0), structural unit (a1-1), and structural unit (a1-2) (preferably structural units having cyclohexyl and cyclopentyl groups), more preferably at least two selected from the group consisting of structural unit (a1-1) and structural unit (a1-2). Structural unit (s) is preferably at least one selected from the group consisting of structural unit (a2) and structural unit (a3). Structural unit (a2) is preferably a structural unit represented by formula (a2-1) or a structural unit represented by formula (a2-A). Structural unit (a3) is preferably at least one selected from the group consisting of a structural unit represented by formula (a3-1), a structural unit represented by formula (a3-2), and a structural unit represented by formula (a3-4).

The structural units constituting resin (A) may be used singly or in combination. They can be produced by known polymerization methods (e.g., free radical polymerization) using monomers that derive these structural units. The content of each structural unit in resin (A) can be adjusted by adjusting the amount of monomer used in the polymerization. The weight-average molecular weight of resin (A) is preferably 2,000 or greater (more preferably 2,500 or greater, and even more preferably 3,000 or greater) and 50,000 or less (more preferably 30,000 or less, and even more preferably 15,000 or less). In this specification, the weight-average molecular weight is the value determined by gel permeation chromatography under the conditions described in the Examples.

<Resins Other Than Resin (A)> The anti-corrosion agent composition of the present invention may contain resins other than resin (A). Examples of resins other than resin (A) include resins containing structural unit (a4) or structural unit (a5) (hereinafter sometimes referred to as "resin (X)").

Among these, the resin (X) is preferably a resin containing the structural unit (a4). In the resin (X), the content of the structural unit (a4) relative to the total of all structural units in the resin (X) is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more. Structural units that the resin (X) may further contain include the structural unit (a2), the structural unit (a3), and structural units derived from other known monomers. Among these, the resin (X) is preferably a resin containing only the structural unit (a4) and/or the structural unit (a5), and more preferably a resin containing only the structural unit (a4). Resin (X) can be composed of a single structural unit or a combination of two or more. It can be produced by a known polymerization method (e.g., free radical polymerization) using monomers derived from these structural units. The content of each structural unit in resin (X) can be adjusted by adjusting the amount of monomer used in the polymerization. The weight-average molecular weight of resin (X) is preferably 6,000 or greater (more preferably 7,000 or greater) and 80,000 or less (more preferably 60,000 or less). The weight-average molecular weight of resin (X) can be determined using the same method as for resin (A). When the anti-corrosion agent composition includes resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, further preferably 1 to 40 parts by mass, further preferably 1 to 30 parts by mass, and particularly preferably 1 to 8 parts by mass, relative to 100 parts by mass of resin (A).

The content of the resin (A) in the anti-corrosion composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, relative to the solid content of the anti-corrosion composition. Furthermore, if a resin other than the resin (A) is included, the combined content of the resin (A) and the resin other than the resin (A) relative to the solid content of the anti-corrosion composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less. The solid content of the anti-corrosion composition and the content of the resin relative to the solid content can be measured by known analytical methods such as liquid chromatography or gas chromatography.

<Acid Generator (B)> Acid generators (B) can be either non-ionic or ionic. Examples of non-ionic acid generators include sulfonates (e.g., 2-nitrobenzyl esters, aromatic sulfonates, oxime sulfonates, N-sulfonyloxyimides, sulfonyloxyketones, and naphthoquinone diazonium 4-sulfonates) and sulfons (e.g., disulfonium, ketone sulfonium, and sulfonyldiazomethane). Ionic acid generators are typically onium salts containing onium cations (e.g., diazonium salts, phosphonium salts, scorchium salts, and iodonium salts). Examples of onium salt anions include sulfonate anions, sulfonylimide anions, and sulfonylmide anions.

As the acid generator (B), compounds that generate an acid upon exposure to radiation, such as those described in Japanese Patent Application Laid-Open Nos. 63-26653, 55-164824, 62-69263, 63-146038, 63-163452, 62-153853, 63-146029, U.S. Patent No. 3,779,778, U.S. Patent No. 3,849,137, German Patent No. 3914407, and European Patent No. 126,712, can be used. Compounds produced by known methods can also be used. Two or more acid generators (B) may be used in combination.

The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)"). [In formula (B1), Q ^b1 and Q ^b2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L ^b1 represents a divalent saturated alkyl group having 1 to 24 carbon atoms, wherein -CH ₂ - in the divalent saturated alkyl group may be substituted with -O- or -CO-, and the hydrogen atom in the divalent saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group. Y represents a methyl group which may have a substituent, or an alicyclic alkyl group which may have a substituent, wherein -CH ₂ - in the alicyclic alkyl group may be substituted with -O-, -S(O) ₂ -, or -CO-. Z1 ⁺ represents an organic cation.]

Examples of the perfluoroalkyl group represented by Q ^b1 and Q ^b2 include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluoro-sec-butyl, perfluoro-tert-butyl, perfluoropentyl, and perfluorohexyl. Q ^b1 and Q ^b2 are preferably each independently a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

Examples of the divalent saturated alkyl group in L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated alkyl group. These groups may also be a group formed by combining two or more of these groups. Specifically, examples include linear alkanediyl groups such as methylene, ethylidene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, and heptadecane-1,17-diyl; Branched alkanediyl groups such as ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent aliphatic saturated alkyl groups such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl, norbornane-2,5-diyl, adamantane-1,5-diyl, and adamantane-2,6-diyl.

Examples of the group in which -CH ₂ - in the divalent saturated alkyl group represented by L ^b1 is substituted with -O- or -CO- include the groups represented by any of Formulas (b1-1) to (b1-3). Furthermore, in the groups represented by Formulas (b1-1) to (b1-3) and the groups represented by Formulas (b1-4) to (b1-11) as specific examples thereof, * and ** represent bonding bonds, and * represents a bonding bond to -Y.

[In formula (b1-1), L ^b2 represents a single bond or a divalent saturated alkyl group having 1 to 22 carbon atoms, wherein the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom. L ^b3 represents a single bond or a divalent saturated alkyl group having 1 to 22 carbon atoms, wherein the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group, and the -CH ₂ - contained in the saturated alkyl group may be substituted with -O- or -CO-. The total number of carbon atoms in L ^b2 and L ^b3 is 22 or less. In formula (b1-2), L ^b4 represents a single bond or a divalent saturated alkyl group having 1 to 22 carbon atoms, wherein the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom. L ^b5 represents a single bond or a divalent saturated alkyl group having 1 to 22 carbon atoms. A hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group, and a -CH ₂ - group contained in the saturated alkyl group may be substituted with -O- or -CO-. The total number of carbon atoms in L ^b4 and L ^b5 is 22 or less. In formula (b1-3), L ^b6 represents a single bond or a divalent saturated alkyl group having 1 to 23 carbon atoms. A hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group. L ^b7 represents a single bond or a divalent saturated alkyl group having 1 to 23 carbon atoms. A hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group, and a -CH ₂ - group contained in the saturated alkyl group may be substituted with -O- or -CO-. The total number of carbon atoms in L ^b6 and L ^b7 is 23 or less. * and ** represent bonding bonds, and * represents a bonding bond with Y.]

Regarding the groups represented by Formulas (b1-1) to (b1-3), when _-CH2- in a saturated alkyl group is substituted with -O- or -CO-, the number of carbon atoms before the substitution is the same as the number of carbon atoms in the saturated alkyl group. Examples of the divalent saturated alkyl group include the same as the divalent saturated alkyl group of ^Lb1 . ^Lb2 is preferably a single bond. ^Lb3 is preferably a divalent saturated alkyl group having 1 to 4 carbon atoms. ^Lb4 is preferably a divalent saturated alkyl group having 1 to 8 carbon atoms, wherein the hydrogen atom in the divalent saturated alkyl group may be substituted with a fluorine atom. ^Lb5 is preferably a single bond or a divalent saturated alkyl group having 1 to 8 carbon atoms. L ^b6 is preferably a single bond or a divalent saturated alkyl group having 1 to 4 carbon atoms, wherein the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom. L ^b7 is preferably a single bond or a divalent saturated alkyl group having 1 to 18 carbon atoms, wherein the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group, and the -CH ₂ - contained in the divalent saturated alkyl group may be substituted with -O- or -CO-.

The group in which -CH ₂ - in the divalent saturated alkyl group represented by L ^b1 is substituted with -O- or -CO- is preferably a group represented by formula (b1-1) or formula (b1-3). Examples of the group represented by formula (b1-1) include the groups represented by formulas (b1-4) to (b1-8). [In formula (b1-4), L ^b8 represents a single bond or a divalent saturated alkyl group having 1 to 22 carbon atoms, wherein the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group. In formula (b1-5), L ^b9 represents a divalent saturated alkyl group having 1 to 20 carbon atoms, wherein -CH ₂ - contained in the divalent saturated alkyl group may be substituted with -O- or -CO-. L ^b10 represents a single bond or a divalent saturated alkyl group having 1 to 19 carbon atoms, wherein the hydrogen atom contained in the divalent saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group. The total number of carbon atoms in L ^b9 and L ^b10 is 20 or less. In formula (b1-6), L ^b11 represents a divalent saturated alkyl group having 1 to 21 carbon atoms. L ^b12 represents a single bond or a divalent saturated alkyl group having 1 to 20 carbon atoms, wherein the hydrogen atom contained in the divalent saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group. The total carbon number of L ^b11 and L ^b12 is 21 or less. In formula (b1-7), L ^b13 represents a divalent saturated alkyl group having 1 to 19 carbon atoms. L ^b14 represents a single bond or a divalent saturated alkyl group having 1 to 18 carbon atoms, wherein the -CH ₂ - group contained in the divalent saturated alkyl group may be substituted with -O- or -CO-. L ^b15 represents a single bond or a divalent saturated alkyl group having 1 to 18 carbon atoms, wherein the hydrogen atom contained in the divalent saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group. The total carbon number of L ^b13 to L ^b15 is 19 or less. In formula (b1-8), L ^b16 represents a divalent saturated alkyl group having 1 to 18 carbon atoms, wherein -CH ₂ - in the divalent saturated alkyl group may be substituted with -O- or -CO-. L ^b17 represents a divalent saturated alkyl group having 1 to 18 carbon atoms. L ^b18 represents a single bond or a divalent saturated alkyl group having 1 to 17 carbon atoms, wherein the hydrogen atom in the divalent saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group. The total number of carbon atoms in L ^b16 to L ^b18 is 19 or less. * and ** represent bonding bonds, and * represents a bonding bond with Y. L ^b8 is preferably a divalent saturated alkyl group having 1 to 4 carbon atoms. L ^b9 is preferably a divalent saturated alkyl group having 1 to 8 carbon atoms. L ^b10 is preferably a single bond or a divalent saturated alkyl group having 1 to 19 carbon atoms, more preferably a single bond or a divalent saturated alkyl group having 1 to 8 carbon atoms. L ^b11 is preferably a divalent saturated alkyl group having 1 to 8 carbon atoms. L ^b12 is preferably a single bond or a divalent saturated alkyl group having 1 to 8 carbon atoms. L ^b13 is preferably a divalent saturated alkyl group having 1 to 12 carbon atoms. L ^b14 is preferably a single bond or a divalent saturated alkyl group having 1 to 6 carbon atoms. L ^b15 is preferably a single bond or a divalent saturated alkyl group having 1 to 18 carbon atoms, more preferably a single bond or a divalent saturated alkyl group having 1 to 8 carbon atoms. L ^b16 is preferably a divalent saturated alkyl group having 1 to 12 carbon atoms. L ^b17 is preferably a divalent saturated alkyl group having 1 to 6 carbon atoms. L ^b18 is preferably a single bond or a divalent saturated alkyl group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated alkyl group having 1 to 4 carbon atoms.

Examples of the group represented by formula (b1-3) include groups represented by formulas (b1-9) to (b1-11). [In formula (b1-9), L ^b19 represents a single bond or a divalent saturated alkyl group having 1 to 23 carbon atoms, wherein the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom. L ^b20 represents a single bond or a divalent saturated alkyl group having 1 to 23 carbon atoms, wherein the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom, a hydroxyl group, or an alkylcarbonyloxy group. The -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. The total number of carbon atoms contained in L ^b19 and L ^b20 is 23 or less. In formula (b1-10), L ^b21 represents a single bond or a divalent saturated alkyl group having 1 to 21 carbon atoms, wherein the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom. L ^b22 represents a single bond or a divalent saturated alkyl group having 1 to 21 carbon atoms. L ^b23 represents a single bond or a divalent saturated alkyl group having 1 to 21 carbon atoms, and the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom, a hydroxyl group, or an alkylcarbonyloxy group. The -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. The total number of carbon atoms in L ^b21 , L ^b22 , and L ^b23 is 21 or less. * and ** represent bonding bonds, and * represents a bonding bond with Y. In formula (b1-11), L ^b24 represents a single bond or a divalent saturated alkyl group having 1 to 20 carbon atoms, and the hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom. L ^b25 represents a divalent saturated alkyl group having 1 to 21 carbon atoms. L ^b26 represents a single bond or a divalent saturated alkyl group having 1 to 20 carbon atoms. The hydrogen atom contained in the saturated alkyl group may be substituted with a fluorine atom, a hydroxyl group, or an alkylcarbonyloxy group. The -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. The total number of carbon atoms in L ^b24 , L ^b25 , and L ^b26 is 21 or less.

Furthermore, with respect to the groups represented by formulas (b1-9) through (b1-11), when a hydrogen atom contained in a saturated alkyl group is substituted with an alkylcarbonyloxy group, the number of carbon atoms before the substitution is the number of carbon atoms in the saturated alkyl group. Examples of alkylcarbonyloxy groups include acetyloxy, propionyloxy, butyryloxy, cyclohexylcarbonyloxy, and adamantylcarbonyloxy.

Examples of the group represented by formula (b1-4) include the following. (* and ** indicate binding bonds, and * indicates the bond with Y.)

Examples of the group represented by formula (b1-5) include the following. (* and ** indicate binding bonds, and * indicates the bond with Y.)

Examples of the group represented by formula (b1-6) include the following. (* and ** indicate binding bonds, and * indicates the bond with Y.)

Examples of the group represented by formula (b1-7) include the following. (* and ** indicate binding bonds, and * indicates the bond with Y.)

Examples of the group represented by formula (b1-8) include the following. (* and ** indicate binding bonds, and * indicates the bond with Y.)

Examples of the group represented by formula (b1-2) include the following. (* and ** indicate binding bonds, and * indicates the bond with Y.)

Examples of the group represented by formula (b1-9) include the following. (* and ** indicate binding bonds, and * indicates the bond with Y.)

Examples of the group represented by formula (b1-10) include the following. (* and ** indicate binding bonds, and * indicates the bond with Y.)

Examples of the group represented by formula (b1-11) include the following. (* and ** indicate binding bonds, and * indicates the bond with Y.)

Examples of the alicyclic alkyl group represented by Y include groups represented by formulas (Y1) to (Y11) and (Y36) to (Y38). When the _-CH2- group contained in the alicyclic alkyl group represented by Y is substituted with -O-, -S(O) _2- , or -CO-, the number of such groups may be one or two or more. Examples of such groups include groups represented by formulas (Y12) to (Y35) and (Y39) to (Y43). The alicyclic alkyl group represented by Y is preferably a group represented by any one of Formulas (Y1) to (Y20), (Y26), (Y27), (Y30), (Y31), (Y39) to (Y43), more preferably a group represented by Formula (Y11), (Y15), (Y16), (Y20), (Y26), (Y27), (Y30), (Y31), (Y39), (Y40), (Y42) or (Y43), and further preferably a group represented by Formula (Y11), (Y15), (Y20), (Y26), (Y27), (Y30), (Y31), (Y39), (Y40), (Y42) or (Y43). When the alicyclic alkyl group represented by Y is a spirocyclic ring containing an oxygen atom, such as those of formula (Y28) to (Y35), (Y39) to (Y40), (Y42), or (Y43), the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. Furthermore, the methylene group adjacent to the oxygen atom in the alkanediyl group contained in the ketal structure is preferably unsubstituted with a fluorine atom.

Examples of the substituent for the methyl group represented by Y include a halogen atom, a hydroxyl group, an alicyclic alkyl group having 3 to 16 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, a glycidyloxy group, a -(CH ₂ ) _ja -CO-OR ^b1 group, or a -(CH ₂ ) _ja -O-CO-R ^b1 group (wherein R ^b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic alkyl group having 3 to 16 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, or a combination thereof; -CH ₂ - contained in the alkyl group and the alicyclic alkyl group may be substituted with -O-, -SO ₂ -, or -CO-; and a hydrogen atom contained in the alkyl group, the alicyclic alkyl group, or the aromatic alkyl group may be substituted with a hydroxyl group or a fluorine atom; and ja represents any integer from 0 to 4). Examples of the substituents of the alicyclic alkyl group represented by Y include a halogen atom, a hydroxyl group, an alkyl group having 1 to 16 carbon atoms which may be substituted with a hydroxyl group ( _-CH2- in the alkyl group may be substituted with -O- or -CO-), an alicyclic alkyl group having 3 to 16 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidyloxy group, a -( _CH2 ) _ja -CO- ^ORb1 group, or a -( _CH2 ) _ja -O-CO- ^Rb1 group (wherein ^Rb1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic alkyl group having 3 to 16 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, or a combination thereof; _{and -CH2-} in the alkyl group and the alicyclic alkyl group may be substituted with -O-, -SO2-, or _-SO2-. - or -CO-, the hydrogen atom contained in the alkyl group, the alicyclic alkyl group, and the aromatic alkyl group may be substituted with a hydroxyl group or a fluorine atom. ja represents any integer from 0 to 4), etc.

Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. Examples of alicyclic alkyl groups include cyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl, cyclooctyl, norbornyl, and adamantyl. An alicyclic alkyl group may have a chain alkyl group, and examples include methylcyclohexyl and dimethylcyclohexyl. The alicyclic alkyl group preferably has 3 to 12 carbon atoms, more preferably 3 to 10 carbon atoms. Examples of aromatic alkyl groups include phenyl, naphthyl, anthracenyl, biphenylyl, phenanthrenyl, and other aryl groups. Aromatic alkyl groups may have chain or alicyclic alkyl groups. Examples include aromatic alkyl groups having chain alkyl groups with 1 to 18 carbon atoms (such as tolyl, xylyl, cumyl, mesityl, p-methylphenyl, p-ethylphenyl, p-tert-butylphenyl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl), and aromatic alkyl groups having alicyclic alkyl groups with 3 to 18 carbon atoms (such as p-adamantylphenyl and p-cyclohexylphenyl). The number of carbon atoms in the aromatic alkyl group is preferably 6 to 14, more preferably 6 to 10. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, 2-ethylhexyl, octyl, nonyl, decyl, undecyl, and dodecyl. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4. Examples of alkyl groups substituted with a hydroxyl group include hydroxyalkyl groups such as hydroxymethyl and hydroxyethyl. Examples of aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl, and naphthylethyl. Examples of groups in which the _-CH2- group in the alkyl group is substituted with -O-, -S(O) _2- , or -CO- include alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, alkylcarbonyloxy groups, and combinations thereof. Examples of alkoxy groups include methoxy groups, ethoxy groups, propoxy groups, butoxy groups, pentyloxy groups, hexyloxy groups, heptyloxy groups, octyloxy groups, decyloxy groups, and dodecyloxy groups. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4. Examples of the alkoxycarbonyl group include methoxycarbonyl, ethoxycarbonyl, and butoxycarbonyl. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of the alkylcarbonyl group include acetyl, propionyl, and butyryl. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of the alkylcarbonyloxy group include acetyloxy, propionyloxy, and butyryloxy. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of combined groups include groups consisting of an alkoxy group and an alkyl group, groups consisting of an alkoxy group and an alkoxy group, groups consisting of an alkoxy group and an alkylcarbonyl group, and groups consisting of an alkoxy group and an alkylcarbonyloxy group. Examples of combined groups consisting of an alkoxy group and an alkyl group include alkoxyalkyl groups such as methoxymethyl, methoxyethyl, ethoxyethyl, and ethoxymethyl. The number of carbon atoms in the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of combined groups consisting of an alkoxy group and an alkoxy group include alkoxyalkoxy groups such as methoxymethoxy, methoxyethoxy, ethoxymethoxy, and ethoxyethoxy. The number of carbon atoms in the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of groups formed by combining an alkoxy group with an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as methoxyacetyl, methoxypropionyl, ethoxyacetyl, and ethoxypropionyl. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5. Examples of groups formed by combining an alkoxy group with an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as methoxyacetyloxy, methoxypropionyloxy, ethoxyacetyloxy, and ethoxypropionyloxy. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5. Examples of the group in which -CH ₂ - in the alicyclic hydrocarbon group is substituted with -O-, -S(O) ₂ -, or -CO- include the groups represented by formulae (Y12) to (Y35) and (Y39) to (Y43).

As Y, the following can be listed.

Y is preferably an alicyclic alkyl group having 3 to 24 carbon atoms which may be substituted, more preferably an alicyclic alkyl group having 3 to 20 carbon atoms which may be substituted, further preferably an alicyclic alkyl group having 3 to 18 carbon atoms which may be substituted, and further preferably an adamantyl group which may be substituted. The _-CH2- group constituting the alicyclic alkyl group or adamantyl group may be substituted with -CO-, -S(O) _2- , or -CO-. Specifically, Y is preferably an adamantyl group, a hydroxyadadamantyl group, an oxoadadamantyl group, or a group represented by Formula (Y42), (Y100) to (Y114).

As the anion in the salt represented by formula (B1), anions represented by formulas (B1-A-1) to (B1-A-59) are preferred [hereinafter sometimes referred to as "anion (B1-A-1)" etc. corresponding to the formula number], and anions represented by any one of formulas (B1-A-1) to (B1-A-4), (B1-A-9), (B1-A-10), (B1-A-24) to (B1-A-33), (B1-A-36) to (B1-A-40), and (B1-A-47) to (B1-A-59) are more preferred.

Here, R ⁱ² to R ⁱ⁷ are each independently an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. ^{R i8} is, for example, a chain alkyl group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic alkyl group having 5 to 12 carbon atoms, or a group formed by combining these groups, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group. ^{L A41} is a single bond or an alkanediyl group having 1 to 4 carbon atoms. ^{Q b1} and Q ^b2 have the same meanings as described above. Specific examples of the anion in the salt represented by formula (B1) include those described in Japanese Patent Application Laid-Open No. 2010-204646.

Preferred anions in the salt represented by formula (B1) include anions represented by formulas (B1a-1) to (B1a-38).

Among them, anions represented by any one of Formula (B1a-1) to Formula (B1a-3), Formula (B1a-7) to Formula (B1a-16), Formula (B1a-18), Formula (B1a-19), and Formula (B1a-22) to Formula (B1a-38) are preferred.

Examples of the organic cation representing Z1 ⁺ include organic onium cations, organic zirconia cations, organic iodine cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic zirconia cations and organic iodine cations are preferred, and aryl zirconia cations are more preferred. Specifically, examples include cations represented by any of Formulas (b2-1) to (b2-4) (hereinafter sometimes referred to as "cation (b2-1)" etc. according to the formula number). In formula (b2-1) to formula (b2-4), R ^b4 to R ^b6 each independently represents a chain alkyl group having 1 to 30 carbon atoms, an alicyclic alkyl group having 3 to 36 carbon atoms, or an aromatic alkyl group having 6 to 36 carbon atoms; the hydrogen atom contained in the chain alkyl group may be substituted by a hydroxyl group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic alkyl group having 3 to 12 carbon atoms, or an aromatic alkyl group having 6 to 18 carbon atoms; the hydrogen atom contained in the alicyclic alkyl group may be substituted by a halogen atom, an aliphatic alkyl group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group; the hydrogen atom contained in the aromatic alkyl group may be substituted by a halogen atom, a hydroxyl group, an aliphatic alkyl group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R ^b4 and R ^b5 may bond to each other and, together with the sulfur atom to which they are bonded, form a ring. The -CH ₂ - contained in the ring may be substituted with -O-, -S-, or -CO-. R ^b7 and R ^b8 each independently represent a halogen atom, a hydroxyl group, an aliphatic alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent an integer from 0 to 5. When m2 is 2 or greater, multiple R ^b7s may be the same or different. When n2 is 2 or greater, multiple R ^b8s may be the same or different. R ^b9 and R ^b10 each independently represent a chain alkyl group having 1 to 36 carbon atoms or an alicyclic alkyl group having 3 to 36 carbon atoms. R ^b9 and R ^b10 may bond to each other and, together with the sulfur atoms to which they are bonded, form a ring. -CH ₂ - in the ring may be substituted with -O-, -S-, or -CO-. R ^b11 represents a hydrogen atom, a chain alkyl group having 1 to 36 carbon atoms, an alicyclic alkyl group having 3 to 36 carbon atoms, or an aromatic alkyl group having 6 to 18 carbon atoms. R ^b12 represents a chain alkyl group having 1 to 12 carbon atoms, an alicyclic alkyl group having 3 to 18 carbon atoms, or an aromatic alkyl group having 6 to 18 carbon atoms. A hydrogen atom in the chain alkyl group may be substituted with an aromatic alkyl group having 6 to 18 carbon atoms, or a hydrogen atom in the aromatic alkyl group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. ^Rb11 and ^Rb12 may be bonded to each other to form a ring including the bonded -CH-CO-. The _-CH2- contained in the ring may be substituted with -O-, -S-, or -CO-. ^Rb13 to ^Rb18 each independently represent a halogen atom, a hydroxyl group, an aliphatic alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. ^Lb31 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent an integer from 0 to 5. q2 and r2 each independently represent an integer from 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, multiple R ^b13s are the same or different; when p2 is 2 or more, multiple R ^b14s are the same or different; when q2 is 2 or more, multiple R ^b15s are the same or different; when r2 is 2 or more, multiple R ^b16s are the same or different; when s2 is 2 or more, multiple R ^b17s are the same or different; and when t2 is 2 or more, multiple R ^b18s are the same or different.

The term "aliphatic alkyl" refers to chain alkyl and alicyclic alkyl groups. Examples of chain alkyl groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. In particular, chain alkyl groups with R ^b9 to R ^b12 preferably have 1 to 12 carbon atoms. Alicyclic alkyl groups may be monocyclic or polycyclic. Examples of monocyclic alicyclic alkyl groups include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Examples of the polycyclic alicyclic alkyl group include decahydronaphthyl, adamantyl, norbornyl, and the following groups. In particular, the alicyclic alkyl groups represented by R ^b9 to R ^b12 preferably have 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.

Examples of alicyclic alkyl groups in which a hydrogen atom is substituted with an aliphatic alkyl group include methylcyclohexyl, dimethylcyclohexyl, 2-methyladamantan-2-yl, 2-ethyladamantan-2-yl, 2-isopropyladamantan-2-yl, methylnorbornyl, and isobornyl. In alicyclic alkyl groups in which a hydrogen atom is substituted with an aliphatic alkyl group, the total carbon number of the alicyclic alkyl group and the aliphatic alkyl group is preferably 20 or less. The term "fluorinated alkyl group" refers to an alkyl group having 1 to 12 carbon atoms and includes fluoromethyl, difluoromethyl, trifluoromethyl, and perfluorobutyl. The fluorinated alkyl group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms.

Examples of aromatic alkyl groups include phenyl, biphenyl, naphthyl, and phenanthrenyl. Aromatic alkyl groups may have a chain alkyl group or an alicyclic alkyl group. Examples include aromatic alkyl groups having a chain alkyl group (such as tolyl, xylyl, cumyl, mesityl, p-ethylphenyl, p-tert-butylphenyl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl) and aromatic alkyl groups having an alicyclic alkyl group (such as p-cyclohexylphenyl and p-adamantylphenyl). When the aromatic alkyl group has a chain alkyl group or an alicyclic alkyl group, chain alkyl groups having 1 to 18 carbon atoms and alicyclic alkyl groups having 3 to 18 carbon atoms are preferred. Examples of aromatic hydrocarbon groups in which a hydrogen atom is substituted with an alkoxy group include p-methoxyphenyl. Examples of chain hydrocarbon groups in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl, and naphthylethyl.

Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy, and dodecyloxy. Examples of alkylcarbonyl groups include acetyl, propionyl, and butyryl. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. Examples of alkylcarbonyloxy groups include methylcarbonyloxy, ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, butylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, pentylcarbonyloxy, hexylcarbonyloxy, octylcarbonyloxy, and 2-ethylhexylcarbonyloxy.

The ring formed by R ^b4 and R ^b5 , together with the sulfur atom to which they are bonded, can be monocyclic, polycyclic, aromatic, non-aromatic, saturated, or unsaturated. Examples of such rings include those with 3 to 18 carbon atoms, preferably those with 4 to 18 carbon atoms. Examples of rings containing sulfur atoms include those with 3 to 12 members, preferably those with 3 to 7 members. Examples include the following rings. * indicates a bond.

The ring formed by R ^b9 and R ^b10 together can be monocyclic, polycyclic, aromatic, non-aromatic, saturated, or unsaturated. Examples of such rings include 3- to 12-membered rings, preferably 3- to 7-membered rings. Examples include thiocyclopentane-1-ring (tetrahydrothiophene ring), thiocyclohexane-1-ring, and 1,4-oxothicyclohexane-4-ring. The ring formed by R ^b11 and R ^b12 together can be monocyclic, polycyclic, aromatic, non-aromatic, saturated, or unsaturated. The ring may be a 3- to 12-membered ring, preferably a 3- to 7-membered ring, and examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxadamantane ring.

Of cations (b2-1) to (b2-4), cations (b2-1) are preferred. Examples of cations (b2-1) include the following.

The following cations can be listed as cations (b2-2).

As cations (b2-3), the following cations can be listed.

The following cations can be listed as cations (b2-4).

The acid generator (B) is a combination of the aforementioned anion and the aforementioned organic cation, and any combination of these may be used. Preferred acid generators (B) are combinations of anions represented by any of Formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38), and cations (b2-1), (b2-3), or (b2-4).

Preferred acid generators (B) include those represented by Formulae (B1-1) to (B1-56). Among these, those containing an aryl calcium cation are preferred, with those represented by Formulae (B1-1) to (B1-3), (B1-5) to (B1-7), (B1-11) to (B1-14), (B1-20) to (B1-26), (B1-29), and (B1-31) to (B1-56) being particularly preferred.

In the anti-corrosion agent composition of the present invention, the content of the acid generator relative to 100 parts by mass of the resin (A) is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, further preferably 3 parts by mass or more and 40 parts by mass or less, and further preferably 10 parts by mass or more and 40 parts by mass or less.

<Solvent (E)> The content of the solvent (E) in the resist composition is generally 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, and more preferably 94% by mass or more and 99% by mass or less. The content of the solvent (E) can be measured by known analytical methods such as liquid chromatography or gas chromatography. Examples of the solvent (E) include glycol ether esters such as ethyl cellulosic acetate, methyl cellulosic acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; and cyclic esters such as γ-butyrolactone. A single solvent (E) may be used, or two or more may be used.

<Quencher (C)> Examples of the quencher (C) include alkaline nitrogen-containing organic compounds and salts derived from acids weaker than the acid generated from the acid generator (B). When the anti-etching agent composition contains the quencher (C), the content of the quencher (C) is preferably approximately 0.01% to 15% by mass, more preferably approximately 0.01% to 10% by mass, further preferably approximately 0.1% to 5% by mass, and further preferably approximately 0.1% to 3% by mass, based on the solid content of the anti-etching agent composition. Examples of alkaline nitrogen-containing organic compounds include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Examples of aliphatic amines include primary amines, diamines, and tertiary amines. Examples of amines include: 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-methylaniline, 3-methylaniline or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, and trihexylamine. , triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris〔2-(2-methoxyethoxy)ethyl〕amine, triisopropanolamine, ethylenediamine, tetramethylene diamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenedianiline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-bis(2-pyridyl)ethane, 1,2-bis(4-pyridyl)ethane, 1,2-bis(2- The following examples include 1,2-bis(4-pyridyl)ethylene, 1,3-bis(4-pyridyl)propane, 1,2-bis(4-pyridyloxy)ethane, di(2-pyridyl)ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dimethylpyridylamine, bipyridine, etc., preferably diisopropylaniline, and more preferably 2,6-diisopropylaniline. Examples of ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, and choline.

The acidity of a salt generated from an acid that is weaker than the acid generated from the acid generator (B) is expressed in terms of its acid dissociation constant (pKa). A salt generated from an acid that is weaker than the acid generated from the acid generator (B) is one for which the acid dissociation constant of the acid generated from the salt is generally -3 < pKa, preferably -1 < pKa < 7, and even more preferably 0 < pKa < 5. Examples of salts generated from acids weaker in acidity than the acid generated from the acid generator (B) include salts represented by the following formula, salts represented by formula (D) described in Japanese Patent Application Laid-Open No. 2015-147926 (hereinafter sometimes referred to as "weak acid intramolecular salt (D)"), and salts described in Japanese Patent Application Laid-Open No. 2012-229206, Japanese Patent Application Laid-Open No. 2012-6908, Japanese Patent Application Laid-Open No. 2012-72109, Japanese Patent Application Laid-Open No. 2011-39502, and Japanese Patent Application Laid-Open No. 2011-191745. Preferred are salts derived from carboxylic acids that are weaker in acidity than the acid generated from the acid generator (B) (salts having a carboxylate anion), and more preferably, weak acid intramolecular salts (D).

The following salts can be listed as intramolecular salts of weak acids (D).

<Other Components> The anti-corrosion agent composition of the present invention may optionally contain other components other than those listed above (hereinafter sometimes referred to as "other components (F)"). Other components (F) are not particularly limited and may be additives known in the anti-corrosion agent field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes.

<Preparation of the Anti-Corrosion Agent Composition> The anti-corrosion agent composition of the present invention can be prepared by mixing compound (I), resin (A), and acid generator (B), and optionally, resins other than resin (A), solvent (E), quencher (C), and other components (F). The order of mixing is arbitrary and not particularly limited. The mixing temperature can be selected from 10°C to 40°C, depending on the type of resin and its solubility in the solvent (E). The mixing time can be selected from 0.5 hours to 24 hours, depending on the mixing temperature. Furthermore, the mixing method is not particularly limited, and stirring can be used. After mixing the ingredients, it is preferably filtered using a filter with a pore size of approximately 0.003 μm to 0.2 μm.

<Method for producing an anti-etching pattern> The method for producing an anti-etching pattern of the present invention comprises: (1) applying the anti-etching composition of the present invention on a substrate; (2) drying the applied composition to form a composition layer; (3) exposing the composition layer; (4) heating the exposed composition layer; and (5) developing the heated composition layer. When applying the anti-etching composition on the substrate, it can be carried out by a commonly used device such as a spin coater. As the substrate, an inorganic substrate such as a silicon wafer can be listed. Before applying the resist composition, the substrate may be cleaned, or an anti-reflective film may be formed on the substrate. The applied composition is dried to remove the solvent, thereby forming a composition layer. Drying is performed, for example, by using a heating device such as a hot plate to evaporate the solvent (so-called pre-baking), or by using a pressure reduction device. The heating temperature is preferably 50°C to 200°C, and the heating time is preferably 10 seconds to 180 seconds. In addition, the pressure during pressure reduction drying is preferably about 1 Pa to 1.0×10 ⁵ Pa. The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. Exposure light sources include those that emit ultraviolet light, such as KrF excimer lasers (wavelength 248 nm), ArF excimer lasers (wavelength 193 nm), and _F₂ excimer lasers (wavelength 157 nm); those that emit higher-harmonic laser light in the far ultraviolet or vacuum ultraviolet regions by wavelength-converting laser light from solid-state laser sources (such as YAG or semiconductor lasers); and those that irradiate electron beams or extreme ultraviolet (EUV) light. In this specification, irradiation with these radiations is sometimes collectively referred to as "exposure." Exposure is typically performed through a mask corresponding to the desired pattern. However, when the exposure light source is an electron beam, direct drawing without a mask is also possible. In order to promote the deprotection reaction of the acid-labile groups, the exposed component layer is subjected to a heat treatment (so-called post-exposure bake). The heating temperature is generally around 50°C to 200°C, preferably around 70°C to 150°C. A developing device is generally used to develop the heated component layer using a developer. Examples of developing methods include immersion, coating, spraying, and dynamic dispense. The developing temperature is preferably, for example, 5°C to 60°C, and the developing time is preferably, for example, 5 seconds to 300 seconds. By selecting the type of developer as follows, a positive resist pattern or a negative resist pattern can be produced. When producing a positive-tone resist pattern using the resist composition of the present invention, an alkaline developer is used as the developer. Any alkaline aqueous solution used in the field can be used. Examples include aqueous solutions of tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline). The alkaline developer may also contain a surfactant. The developed resist pattern is preferably rinsed with ultrapure water to remove any remaining water from the substrate and the pattern. When producing a negative resist pattern using the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as an "organic developer") is used as a developer. Examples of organic solvents contained in organic developers include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole. In an organic developer, the content of an organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and preferably it is substantially only an organic solvent. Among these, an organic developer preferably contains butyl acetate and/or 2-heptanone. In an organic developer, the combined content of butyl acetate and 2-heptanone is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and preferably it is substantially only butyl acetate and/or 2-heptanone. The organic developer may also contain a surfactant. Furthermore, the organic developer may also contain a trace amount of water. During development, development can be stopped by replacing the organic developer with a different solvent. The developed resist pattern is preferably cleaned with a rinse solution. The rinse solution is not particularly limited, as long as it does not dissolve the resist pattern. Solutions containing common organic solvents can be used, preferably alcohol or ester solvents. After cleaning, any residual rinse solution on the substrate and pattern is preferably removed.

<Applications> The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, ArF excimer laser exposure, electron beam (EB) exposure, or EUV exposure. It is particularly suitable as a resist composition for electron beam (EB) exposure or EUV exposure, and is useful in semiconductor microfabrication. [Examples]

The present invention will be described in more detail with reference to examples. In the examples, "%" and "parts" indicating content or usage are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions. Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation) Column: TSK gel Multipore H _XL -M × 3+ guard column (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min Detector: RI detector Column temperature: 40°C Injection volume: 100 μl Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

The structures of the compounds were confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100, MASS: Agilent LC/MSD). In the following examples, the molecular ion peak values are represented by "MASS."

Resin Synthesis The compounds (monomers) used in the synthesis of Resin (A) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-1-3)" etc. according to their formula numbers.

Synthesis Example 1 [Synthesis of Resin A1] Monomers (a1-1-3), monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2), and monomer (a1-4-2) were used and mixed in a molar ratio of [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-2)] of 20:35:3:15:27. Furthermore, 1.5 times the mass of methyl isobutyl ketone was added to the monomer mixture relative to the total mass of all monomers. To the resulting mixture, 1.2 mol% and 3.6 mol% of azobis(2,4-dimethylvaleronitrile) as initiators were added, respectively, relative to the total monomer content. The mixture was heated at 73°C for approximately 5 hours. A 2.5 wt% aqueous solution of p-toluenesulfonic acid was then added to the polymerization reaction mixture, stirred for 12 hours, and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and recovered. Resin A1 with a weight-average molecular weight of approximately 5.3× ^10³ was obtained in a 63% yield. Resin A1 has the following structural units:

Synthesis Example 2 [Synthesis of Resin A2] Monomers used were monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2), and monomer (a1-4-13). The monomers were mixed in a molar ratio of [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-13)] of 20:35:3:15:27. Methyl isobutyl ketone was then added to the monomer mixture in an amount of 1.5 times the total mass of all monomers. To the resulting mixture, 1.2 mol% and 3.6 mol% of azobis(isobutyronitrile) and azobis(2,4-dimethylvaleronitrile) as initiators were added, respectively, relative to the total monomer content. The mixture was heated at 73°C for approximately 5 hours. A 2.5 wt% aqueous p-toluenesulfonic acid solution was then added to the polymerization reaction mixture, stirred for 12 hours, and then separated. The polymerization reaction mixture was then poured into a large amount of n-heptane to precipitate the resin, which was then filtered and recovered. Resin A2 with a weight-average molecular weight of approximately 5.1× ^10³ was obtained in a 61% yield. Resin A2 has the following structural units:

<Preparation of the Anti-Corrosion Agent Composition> As shown in Table 1, the following components were mixed and the resulting mixture was filtered through a 0.2 μm pore size fluororesin filter to prepare the anti-corrosion agent composition.

[Table 1] Anti-corrosion agent composition Resin Acid generator (B) Compound (I) Quencher (C) PB/PEB Component 1 A1=10 copies B1-43=3.4 servings I-2=0.2 parts C1=0.7 parts 100℃/100℃ Component 2 A2=10 copies B1-43=3.4 servings I-2=0.2 parts C1=0.7 parts 100℃/100℃ Component 3 A1=10 copies B1-43=3.4 servings I-3=0.2 parts C1=0.7 parts 100℃/100℃ Composition 4 A2=10 copies B1-43=3.4 servings I-3=0.2 parts C1=0.7 parts 100℃/100℃ Composition 5 A1=10 copies B1-43=3.4 servings I-4=0.2 parts C1=0.7 parts 100℃/100℃ Component 6 A2=10 copies B1-43=3.4 servings I-4=0.2 parts C1=0.7 parts 100℃/100℃ Composition 7 A1=10 copies B1-43=3.4 servings I-9=0.2 parts C1=0.7 parts 100℃/100℃ Composition 8 A2=10 copies B1-43=3.4 servings I-9=0.2 parts C1=0.7 parts 100℃/100℃ Composition 9 A1=10 copies B1-43=3.4 servings I-10=0.2 parts C1=0.7 parts 100℃/100℃ Composition 10 A2=10 copies B1-43=3.4 servings I-10=0.2 parts C1=0.7 parts 100℃/100℃ Composition 11 A1=10 copies B1-43=3.4 servings I-1=0.2 parts C1=0.7 parts 100℃/100℃ Composition 12 A1=10 copies B1-43=3.4 servings I-12=0.2 parts C1=0.7 parts 100℃/100℃ Composition 13 A1=10 copies B1-43=3.4 servings I-17=0.2 parts C1=0.7 parts 100℃/100℃ Composition 14 A1=10 copies B1-43=3.4 servings I-18=0.2 parts C1=0.7 parts 100℃/100℃ Composition 15 A1=10 copies B1-43=3.4 servings I-23=0.2 parts C1=0.7 parts 100℃/100℃ Composition 16 A1=10 copies B1-43=3.4 servings I-24=0.2 parts C1=0.7 parts 100℃/100℃ Composition 17 A1=10 copies B1-43=3.4 servings I-25=0.2 parts C1=0.7 parts 100℃/100℃ Composition 18 A1=10 copies B1-43=3.4 servings I-26=0.2 parts C1=0.7 parts 100℃/100℃ Composition 19 A1=10 copies B1-43=3.4 servings I-28=0.2 parts C1=0.7 parts 100℃/100℃ Comparative composition 1 A1=10 copies B1-43=3.4 servings IX-1=0.2 parts C1=0.7 parts 100℃/100℃

<Resin> A1: Resin A1 <Acid Generator (B)> B1-43: Salt represented by formula (B1-43) (Synthesized according to the example of Japanese Patent Application Laid-Open No. 2016-47815) <Compound (I)> I-1: Compound represented by formula (I-1) I-2: Compound represented by formula (I-2) I-3: Compound represented by formula (I-3) I-4: Compound represented by formula (I-4) I-9: Compound represented by formula (I-9) I-10: Compound represented by formula (I-10) I-12: Compound represented by formula (I-12) I-17: Compound represented by formula (I-17) I-18: Compound represented by formula (I-18) I-23: Compound represented by formula (I-23) I-24: Compound represented by formula (I-24) I-25: Compound represented by formula (I-25) I-26: Compound represented by formula (I-26) I-28: Compound represented by formula (I-28) IX-1: Compound represented by formula (IX-1) <Quencher (C)> C1: Synthesized using the method described in Japanese Patent Publication No. 2011-39502 <Solvent> Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 100 parts γ-butyrolactone 5 parts

(Evaluation of Electron Beam Exposure of Resist Compositions) A 6-inch silicon wafer was treated with hexamethyldisilazane at 90°C for 60 seconds on a direct hot plate. The resist composition was spin-coated onto the wafer to a film thickness of 0.04 μm. The composition layer was then pre-baked for 60 seconds on a direct hot plate at the temperature shown in the "PB" column in Table 1 to form the composition layer. The composition layer formed on the wafer was then directly patterned with contact holes (40 nm pitch/17 nm diameter) using an electron beam patterner (ELIONIX ELS-F125 125 keV) by varying the exposure dose in steps. After exposure, a post-exposure bake was performed on a hot plate at the temperature shown in the "PEB" column in Table 1 for 60 seconds. The composition layer on the silicon wafer was then developed using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developer for 20 seconds at 23°C using a dynamic dispensing method to obtain a resist pattern.

The effective sensitivity was determined as the exposure dose that resulted in a pore diameter of 17 nm in the resist pattern obtained after development.

<CD Uniformity (CDU) Evaluation> For effective sensitivity, the pore diameter of a pattern with a 17 nm pore diameter was measured 24 times for each hole, and the average value was taken as the average pore diameter for each hole. The average pore diameter of the pattern with a 17 nm pore diameter was measured at 400 locations within the same wafer, and the standard deviation was calculated based on the overall average pore diameter. The results are shown in Table 2. The values in the table represent standard deviations (nm).

[Table 2] Anti-corrosion agent composition CDU Example 1 Component 1 2.59 Example 2 Component 2 2.50 Example 3 Component 3 2.61 Example 4 Composition 4 2.53 Example 5 Composition 5 2.55 Example 6 Composition 6 2.48 Example 7 Composition 7 2.49 Example 8 Composition 8 2.41 Example 9 Composition 9 2.51 Example 10 Composition 10 2.43 Example 11 Composition 11 2.63 Example 12 Composition 12 2.48 Example 13 Composition 13 2.44 Example 14 Composition 14 2.36 Example 15 Composition 15 2.46 Example 16 Composition 16 2.42 Example 17 Composition 17 2.34 Example 18 Composition 18 2.49 Example 19 Composition 19 2.50 Comparative example 1 Comparative composition 1 2.88 Compared with comparative composition 1, compositions 1 to 19 had small standard deviations and good CD uniformity (CDU) evaluations. [Industrial Applicability]

The resist composition containing the compound of the present invention can produce a resist pattern with good CD uniformity (CDU), and is therefore suitable for semiconductor microfabrication and extremely useful industrially.

without

without

Claims (9)

An anti-corrosion agent composition comprising a compound represented by formula (I), a resin having an acid-labile group, an acid generator, and a salt (excluding ammonium salt) of a carboxylic acid having a weaker acidity than the acid generated from the acid generator. [In formula (I), R ¹ represents a halogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms; m1 represents any integer from 1 to 5. When m1 is 2 or greater, multiple R ^1s may be the same or different.] The anti-corrosion agent composition according to claim 1, wherein R ¹ is a fluorine atom, an iodine atom or a trifluoromethyl group. The anti-corrosion agent composition as described in claim 1 or claim 2, wherein m1 is any integer from 1 to 3. The anti-corrosion agent composition according to claim 1 or claim 2, wherein R ¹ contains at least one iodine atom. The anti-corrosion agent composition according to claim 1 or claim 2, wherein the content of the compound (I) is 0.001% by mass to 20% by mass based on the solid content. The anti-corrosion agent composition according to claim 1 or claim 2, wherein the resin having an acid-labile group comprises at least one selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2), [In formula (a1-1) and formula (a1-2), ^La1 and ^La2 each independently represent -O- or *-O-( _CH2 ) _k1 -CO-O-, k1 represents any integer from 1 to 7, and * represents a bond with -CO-; ^Ra4 and ^Ra5 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom; ^Ra6 and ^Ra7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic alkyl group having 3 to 18 carbon atoms, an aromatic alkyl group having 6 to 18 carbon atoms, or a combination thereof; m1 represents any integer from 0 to 14; n1 represents any integer from 0 to 10; and n1' represents any integer from 0 to 3]. The anti-corrosion agent composition according to claim 1 or claim 2, wherein the resin having an acid-labile group further comprises a structural unit represented by formula (a2-A), [In formula (a2-A), R ^a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom; R ^a51 represents a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group; A ^a50 represents a single bond or *-X ^a51 -(A ^a52 -X ^a52 ) _nb -, where * represents a bonding site to the carbon atom to which -R ^a50 is bonded; A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms; X ^a51 and X ^a52 each independently represents -O-, -CO-O-, or -O-CO-; nb represents 0 or 1; mb represents any integer from 0 to 4; when mb is any integer greater than 2, multiple R ^a51s may be the same or different.] The anti-corrosion agent composition according to claim 1 or claim 2, wherein the acid generator comprises a salt represented by formula (B1), [In formula (B1), Q ^b1 and Q ^b2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms; L ^b1 represents a divalent saturated alkyl group having 1 to 24 carbon atoms, wherein -CH ₂ - in the divalent saturated alkyl group may be substituted with -O- or -CO-, and the hydrogen atom in the divalent saturated alkyl group may be substituted with a fluorine atom or a hydroxyl group; Y represents a methyl group which may have a substituent or an alicyclic alkyl group which may have a substituent and wherein -CH ₂ - in the alicyclic alkyl group may be substituted with -O-, -S(O) ₂ -, or -CO-; and Z ⁺ represents an organic cation]. A method for producing an anti-etching pattern comprises: (1) applying the anti-etching composition according to any one of claims 1 to 8 on a substrate; (2) drying the applied composition to form a composition layer; (3) exposing the composition layer; (4) heating the exposed composition layer; and (5) developing the heated composition layer.